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Alcatel Multi-Protocol Label Switching (MPLS) Lab Guide Version 1.1 December 19, 2007 Software Version: 7750 SR OS 4.0 R5 August 2006
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Table of contents Lab 1
Lab Infrastructure and IGP Configuration ...................................6
Section 1.1 – Remote Lab Connection............................................................................7 Section 1.2 – Lab Infrastructure Verification and IGP Configuration............................7 Lab 1 Review Questions .................................................................................................8
Lab 2
Static LSP Configuration .................................................................9
Lab 2 Review Questions ...............................................................................................12
Lab 3
Implementing Provider Core LDP................................................13
Section 3.1 – LDP Session Establishment ....................................................................15 Section 3.2 – Configuring and Verifying the Provider Core for LDP ..........................17 Section 3.3 – Enabling ECMP LDP..............................................................................20 Section 3.4 – Applying Export Policy for Label Distribution ......................................23 Section 3.5 – Configuring Targeted LDP .....................................................................25 Lab 3 Review Questions ...............................................................................................27
Lab 4
Enabling Provider Core OSPF-TE and MPLS............................28
Lab 4 Review Questions ...............................................................................................33
Lab 5
CSPF Based LSPs and LSP Establishment ..................................34
Section 5.1– RSVP-TE LSP Establishment ..................................................................35 Section 5.2– Configuring CSPF Based LSPs................................................................37 Lab 5 Review Questions ...............................................................................................44
Lab 6
Enabling Primary and Secondary LSP Tunnels..........................45
Lab 6 Review Questions ...............................................................................................50
Lab 7
FRR One-to-One Protection ..........................................................51
Lab 7 Review Questions ...............................................................................................56
Lab 8
FRR Facility Backup Protection ...................................................57
Lab 8 Review Questions ...............................................................................................64
Lab Solutions and Answers..................................................................................65 Lab 1 Solution – Lab Infrastructure and IGP Configuration ........................................65 Lab 1 - Review Question Answers................................................................................65 Lab 2 Solution – Configuring a Static LSP...................................................................65 Lab 2 - Review Question Answers................................................................................66 Lab 3 Solution – LDP Implementation .........................................................................66 Lab 3 Section 3.1 Solution – LDP Session Establishment ...........................................66 Lab 3 Section 3.1 - Answers to Exercise Questions .....................................................68 Lab 3 Section 3.2 – Configuring and Verifying the Provider Core for LDP ................68 Lab 3 Section 3.2 - Answers to Exercise Questions .....................................................69 Lab Section 3.3 Solution – Enabling ECMP LDP ........................................................70 Lab 3 Section 3.3 - Answers to Exercise Questions .....................................................70 Lab 3 Section 3.4 Solution – Applying Export Policy for Label Distribution..............71 Lab 3 Section 3.4 - Answers to Exercise Questions .....................................................71 Lab 3 Section 3.5 Solution – Configuring Targeted LDP.............................................72 Lab 3 Section 3.5 - Answers to Exercise Questions .....................................................72 Lab 3 - Review Question Answers................................................................................72
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Lab 4 Solution – Configuring the Provider Core for MPLS.........................................73 Lab 4 - Answers to Exercise Questions ........................................................................73 Lab 4 - Answers to Review Questions..........................................................................74 Lab 5 Solution – CSPF Based LSPs and LSP Establishment .......................................75 Lab 5 Section 5.1 - Answers to Exercise Questions .....................................................76 Lab 5 Section 5.2 - Answers to Exercise Questions .....................................................77 Lab 5 - Answers to Review Questions..........................................................................77 Lab 6 Solution – Enabling Primary and Secondary LSP Tunnels ................................78 Lab 6 - Answers to Exercise Questions ........................................................................78 Lab 6 - Answers to Review Questions..........................................................................79 Lab 7 Solution – FRR One-to-One Link Protection .....................................................80 Lab 7 - Answers to Exercise Questions ........................................................................80 Lab 7 - Answers to Review Questions..........................................................................81 Lab 8 Solution – FRR Facility Bypass..........................................................................81 Lab 8 - Answers to Exercise Questions ........................................................................82 Lab 8 - Answers to Review Questions..........................................................................82
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List of Figures Figure 1-1 Lab Topology Overview...................................................................................... 6 Figure 2-1 Static LSP Configuration.................................................................................... 9 Figure 3-1 Implementing Provider Core LDP.................................................................... 13 Figure 4-1: Enabling Provider Core MPLS ...................................................................... 28 Figure 5-1: CSPF Based LSPs ........................................................................................... 34 Figure 6-1: Enabling Primary and Secondary LSP Tunnels.............................................. 45 Figure 7-1: Enabling FRR One-to-One Protection ............................................................ 51 Figure 8-1: Enabling FRR Facility Bypass ........................................................................ 57
List of Tables Table 1-1 Lab 1 Configuration and Verification Commands ............................................... 7 Table 1-2 Remote Lab Addressing........................................................................................ 7 Table 1-3 Interface IP Addressing........................................................................................ 8 Table 2-1 Lab 2 Configuration and Verification Commands ............................................. 10 Table 2-2 Labels for Static LSPs ........................................................................................ 10 Table 3-1 Lab 3 Configuration and Verification Commands ............................................. 14 Table 4-1 Lab 4 Configuration and Verification Commands ............................................. 29 Table 5-1: Lab 5 Configuration and Verification Commands............................................ 35 Table 6-1: Lab 6 Configuration and Verification Commands............................................ 46 Table 7-1: Lab 7 Configuration and Verification Commands............................................ 52 Table 8-1: Lab 8 Configuration and Verification Commands............................................ 58
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Lab 1
Lab Infrastructure and IGP Configuration
Objective: The purpose of this lab is to verify the operation and physical connectivity of the routers and to configure and verify the IGP routing protocol. The lab topology is shown in Figure 1-1. Additional connection details will be provided by the instructor if required.
Service Provider Core IGP Routing
PE1
10.16.1.0/24
PE 2
10.32.1.0/24
Pod 1
Pod 2 P1
P2 10.x.y.z/24
P3
P4
Pod 3 10.48.1.0/24
Pod 4
10.64.1.0/24
PE 4
PE 3
Figure 1-1 Lab Topology Overview
The Alcatel Multi-protocol Label Switching (MPLS) course labs use 7750 Service Routers for the core infrastructure as shown in Figure 1-1. The 7750 SR Edge (PE) routers and the 7750 SR ‘Core’ (P) routers form the Service Provider Core backbone.
Syntax: The configuration and verification commands required for this Lab are provided in Table 1-1. Each command may have additional parameters possible. Use the ‘?’ character for help and to explore all command line options. Other commands may also be used, including those found in previous courses.
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Lab 1 Command list
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#telnet <management ip address> #configure router ospf area <area #> #configure router ospf area <area #> interface #show port #show router interface #show router ospf status #show router ospf interface #show router ospf neighbor #show router route-table #ping <ip-address> #traceroute <ip-route>
Table 1-1 Lab 1 Configuration and Verification Commands
Section 1.1 – Remote Lab Connection Exercise: 1.
2.
Establish a remote connection to the routers, using the addresses from Table 1-2. The username and password for all routers is ‘admin’. If you are unable to connect or login to any of the routers, notify your instructor. Please do not change the admin password unless instructed to do so. Change the bof to use a new configuration file and then save the configuration to this file. The default is set up as read-only, so you will be unable to save to this file. If you have not worked on the 7750 before and need assistance in this step, ask your instructor for help.
Pod Number
Management Address
Pod 1 - Core1 (P1) Edge1 (PE1) Pod 2 - Core2 (P2) Edge2 (PE2) Pod 3 - Core3 (P3) Edge3 (PE3) Pod 4 - Core4 (P4) Edge4 (PE4)
Table 1-2 Remote Lab Addressing
Section 1.2 – Lab Infrastructure Verification and IGP Configuration Exercise: 1.
Refer to Figure 1-1. Familiarize yourself with Lab topology.
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3.
4. 5. 6.
7. 8. 9.
Configure the cards, MDAs and physical ports, using the appropriate show and config commands. If you are not familiar with this process, ask your instructor for assistance. Configure the IP addresses of all interfaces as shown in Table 1-3 using the appropriate commands. In order to make addressing consistent, the last octet of a routerâ&#x20AC;&#x2122;s IP address will always be the same, using the last octet of the management address from Table 1-2. Enable OSPF routing on your PE and P routers. Use one area (area 0). Enable OSPF on all interfaces. Verify the configuration and operation of the IGP. The routing table of your routers should have all the domain networks listed. Refer to Table 1-3 for a list of subnet addresses. If 4 pods are in use, the networks should include the following: a. 10 Ethernet segments b. 8 system addresses Check with your instructor if you are not sure of the number of networks that should be visible. Make note of the configured addresses or other parameters on the diagram if required. All destinations should be reachable. Verify the routing topology using available tools such as ping or traceroute.
Parameter
Value
Pod Number
x = 1, 2, 3, or 4
7750 SR router you are configuring
P___ or PE___
Last octet of management address from Table 1-2
y = ______ (Use as the last octet of all addresses)
System IP address
10.10.10.y/32
(circle your Pod number)
For the last octet of the interface address use the last octet of the routerâ&#x20AC;&#x2122;s management address from Table 1-2 Core 1 to Edge 1 subnet
10.16.1.y/24
Core 2 to Edge 2 subnet
10.32.1.y/24
Core 3 to Edge 3 subnet
10.48.1.y/24
Core 4 to Edge 4 subnet
10.64.1.y/24
Core 1 to Core 2 subnet
10.1.2.y/24
Core 1 to Core 3 subnet
10.1.3.y/24
Core 1 to Core 4 subnet
10.1.4.y/24
Core 2 to Core 3 subnet
10.2.3.y/24
Core 2 to Core 4 subnet
10.2.4.y/24
Core 3 to Core 4 subnet
10.3.4.y/24
Table 1-3 Interface IP Addressing
Lab 1 Review Questions 1. 2. 3.
What is the routed path between your PE router and all other PE routers under normal circumstances? Verify with a traceroute between PE devices. Are other paths possible? What is the next-hop to reach PE1 from your P router? What is the value of the OSPF metric of each link?
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Lab 2
Static LSP Configuration
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Objective: The purpose of this lab is to configure a static LSP from your PE router across the provider core to another PE router as shown in Figure 2-1, and to understand the label operations performed on packets that would be routed along this LSP.
Service Provider Network Static LSP
PE1
Static LSP
Static LSP
Pod 1
P1
P3
PE 2
Pod 2 Static LSP
P2
Static LSP
P4
Pod 3 Static LSP
Static LSP
Pod 4
PE 4
PE3
Figure 2-1 Static LSP Configuration
Syntax: The configuration and verification commands required for this Lab are provided in Table 2-1. Refer to the student guide for additional command details. Each command may have additional parameters possible. Use the â&#x20AC;&#x2DC;?â&#x20AC;&#x2122; character for help and to explore all command line options. Other commands may also be used, including those found in previous exercises and courses.
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Lab 2 Command List
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#configure router mpls #configure router mpls interface <interface-name> #configure router mpls static-lsp <lsp-name> to <destination-ip-address> #configure router mpls static-lsp <lsp-name> push <label> nexthop <ip-address> #configure router mpls interface <interface-name> label-map <in-label > swap <out-label> nexthop <ip-address> #configure router mpls interface <interface-name> label-map <in-label > pop #info (from all contexts) #exit [all] (from all contexts) #admin save #show router mpls label <label range> in-use #show router mpls static-lsp <lsp-name> [transit | terminate] #show router mpls status
Table 2-1 Lab 2 Configuration and Verification Commands
Exercise: Configure a Static LSP as shown in Figure 2-1across the provider core by completing the following steps. Use the labels provided in Table 2-2. NOTE: Recall that an LSP is unidirectional, thus you will configure an LSP from your PE router to your neighbor’s PE router while your neighbor will configure an LSP from their PE router to your PE. You will have to work with your neighboring Pod as they will be responsible for configuring the portion of your LSP that traverses their P and PE routers, while you will be responsible for configuring the portion of their LSP that traverses your P and PE routers. 1. 2. 3. 4. 5.
Configure a static LSP originating on your PE router and going to your adjacent P router. Configure the cross-connection for the static LSP on your P router going to your neighbor’s P router. The outgoing interface must be added to MPLS even though no configuration is required. Your neighbor will configure the remainder of your LSP on their P and PE routers. Configure the remainder of your neighbor’s LSP. On your P router configure the cross-connection for the static LSP coming from your neighbor’s P router and going to your PE router. On your PE router configure the termination of your neighbor’s LSP coming from your P router.
Pods
Edge to Core Label
Core to Core Label
Core to Edge Label
Pod 1 and Pod 3
999
998
997
Pod 2 and Pod 4
597
598
599
Table 2-2 Labels for Static LSPs 6.
On your PE router verify that the static LSP originating on the router is configured and active. Also verify that the LSP (from your neighbor’s PE router) terminating on your PE router is configured and active. Examples of the output you should see are shown below.
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A:PE1# show router mpls static-lsp
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=============================================================================== MPLS Static LSPs (Originating) =============================================================================== LSP Name To Next Hop Out Label Out I/F Adm Opr ------------------------------------------------------------------------------PE1 to PE2 10.10.10.242 10.16.1.221 999 1/2/1 Up Up ------------------------------------------------------------------------------LSPs : 1 =============================================================================== A:PE1#
A:PE1# show router mpls static-lsp terminate =============================================================================== MPLS Static LSPs (Terminate) =============================================================================== In Label In I/F Out Label Out I/F Next Hop Adm Opr ------------------------------------------------------------------------------599 1/2/1 n/a n/a n/a Up Up ------------------------------------------------------------------------------LSPs : 1 ===============================================================================
7.
On your P router verify that the transit LSPs going to your neighbor’s PE and coming from your neighbor’s PE are configured and active. An example is shown below. A:P1# show router mpls static-lsp transit =============================================================================== MPLS Static LSPs (Transit) =============================================================================== In Label In I/F Out Label Out I/F Next Hop Adm Opr ------------------------------------------------------------------------------999 1/1/1 998 1/1/2 10.1.2.2 Up Up 598 1/1/2 597 1/1/1 10.16.1.2 Up Up ------------------------------------------------------------------------------LSPs : 2 ===============================================================================
8.
On your PE router verify the labels in use by the configured static LSPs. An example is shown below. A:PE1# show router mpls label 32 131071 in-use ================================================================ MPLS Labels from 32 to 131071 (In-use) ================================================================ Label Label Type Label Owner ---------------------------------------------------------------597 static-lsp RSVP ---------------------------------------------------------------In-use labels (Owner: All) in specified range : 1 In-use labels in entire range : 1 ================================================================
9.
On your PE and P routers verify the status of the static LSPs. An example is shown below.
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A:PE1# show router mpls status =============================================================================== MPLS Status =============================================================================== Admin Status : Up Oper Status : Up FR Object : Enabled Resignal Timer : Disabled LSP Counts Originate Transit Terminate ------------------------------------------------------------------------------Static LSPs 1 0 1 Dynamic LSPs 0 0 0 Detour LSPs 0 0 0 =============================================================================== A:PE1#
A:P1# show router mpls status =============================================================================== MPLS Status =============================================================================== Admin Status : Up Oper Status : Up FR Object : Enabled Resignal Timer : Disabled LSP Counts Originate Transit Terminate ------------------------------------------------------------------------------Static LSPs 0 2 0 Dynamic LSPs 0 0 0 Detour LSPs 0 0 0 ===============================================================================
10. On your PE and P routers shutdown and disable MPLS support. Use the ‘show router status’ command to verify that MPLS is not supported on your P and PE routers.
Lab 2 Review Questions 1. 2. 3. 4. 5.
How many static LSPs are required between 2 routers to create an end to end path? Which range of label values is reserved for static LSP configurations? How many originating, transiting and terminating LSPs should you see on your PE router? What about on the P router? What is the value of the label that appears on the packet coming in on your P router from your neighbor’s P router? What is the value of the label that is POPed by your PE router?
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Lab 3
Implementing Provider Core LDP
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Objective: This lab has the following objectives: 1. To view the packet exchanged between two routers during the establishment of the LDP session. 2. To enable the provider core for LDP support, enabling and verifying LDP on all required interfaces. 3. To identify the labels generated and distributed for each FEC by default and hence to map out the labels used for an LSP associated with a given FEC. To generate labels for other prefixes using Export Policies. 4. To enable LDP ECMP and view the impact on the LFIB. 5. To configure targeted LDP session between remote routers.
LDP
Service Provider Network LDP Enabled Core
Edge 1
10.16.1.0/24
Edge 2
10.32.1.0/24
Pod 1
Pod 2 Core 1
Core 2 10.x.y.z/24
Core 3
Core 4
Pod 3 10.48.1.0/24
Pod 4
10.64.1.0/24
Edge 4
Edge 3
Figure 3-1 Implementing Provider Core LDP
Syntax: The configuration and verification commands required for this Lab are provided in Table 3-1. Refer to the student guide for additional command details. Each command may have additional parameters possible. Use the â&#x20AC;&#x2DC;?â&#x20AC;&#x2122; character for help and to explore all command line options. Other commands may also be used, including those found in previous exercises and courses.
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Lab 3 Command list
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#configure router ldp interface-parameters interface <interface-name> #configure router ldp targeted-session [no] disable-targeted-session #configure router ldp targeted-session peer <peer-ip-address> #configure router ldp peer-parameters peer <peer-address> authentication-key <key> #configure router ldp export <export-policy-name> #configure>router>policy-options# begin #configure>router>policy-options# policy-statement <policy-name> #configure>router>policy-options>policy-statement# entry <entry index> #configure>router>policy-options>policy-statement>entry# action accept #configure>router>policy-options# commit #clear router ldp session <neighbor-ip-address> #show router status #show router route-table #show router ldp status #show router ldp parameters #show router ldp discovery [detail] #show router ldp interface #show router ldp session #show router ldp bindings #show router ldp bindings active #show router ldp tunnel-table #oam lsp-ping prefix <ip-address> #oam lsp-trace prefix <ip-address> #debug router ldp interface <interface name> packet hello detail #debug router ldp peer <peer address> packet [hello | init | keepalive | label] detail #debug router ldp peer <peer address> event [bindings | message] detail info (from all contexts) exit [all] (from all contexts) #admin save <file-name>
Table 3-1 Lab 3 Configuration and Verification Commands
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Section 3.1 – LDP Session Establishment
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1.
On your PE and P routers configure a log to capture the LDP packets exchanged during session establishment using debug-trace, as follows (this log-id configuration will send the results of the packet capture to the session):
#-------------------------------------------------echo "Log Configuration" #-------------------------------------------------log-id 74 from debug-trace to session exit ----------------------------------------------
2.
Enable event debug on your PE router’s LDP session to your peer P router, as well as the interface, and vice-versa, to capture event messages and bindings exchanged between the routers during LDP session establishment.
3.
On your P router enable LDP on the interface to your PE router and on your PE router enable LDP on the interface to your P router. Observe the LDP messages exchanged between the routers to establish the LDP session. The output is shown in the solutions section at the end of the lab guide. a. After the hello adjacency is established what must happen before the LDP session can be established? b. What state occurs after the Active router sends the Initialization message? c. When can label advertisement start occurring?
4. 5.
Disable debug on your PE and P routers. Enable packet debug on your PE router’s LDP session to your peer P router, and vice-versa, to capture Hello, Initialization, Keep Alive and Label Advertisement packets.
Note: Enabling debug on the interface only captures the interface Hellos while enabling debug on peer captures the targeted Hello, Initialization, Keep Alive and Label Advertisement messages. Use the ‘detail’ keyword to obtain more details for each packet. 6. 7.
8.
On your P router shutdown the LDP interface to your PE router. a. What LDP message is sent to the PE router? On your P router re-enable the LDP interface to your PE router. Observe the LDP messages exchanged between the routers to establish the LDP session. An example is shown below. a. Which router plays the active role? Disable debug on your PE and P routers.
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A:P3>debug router ldp peer 10.10.10.243 packet init detail 56 2006/09/19 23:42:53.36 UTC MINOR: DEBUG #2001 - LDP "LDP: LDP Recv Initialization packet (msgId = 2) from 10.10.10.243:0 Recv 10.10.10.223:0 Protocol version = 1 Keepalive Timeout = 30 Label Advertisement = downStreamUnsolicited Loop Detection = Off PathVector Limit = 0 Max Pdu = 4096 " 57 2006/09/19 23:42:53.36 UTC MINOR: DEBUG #2001 - LDP "LDP: LDP Send Initialization packet (msgId 2) to 10.10.10.243:0 Send 10.10.10.243:0 Protocol version = 1 Keepalive Timeout = 30 Label Advertisement = downStreamUnsolicited Loop Detection = Off PathVector Limit = 0 Max Pdu = 4096 " 58 2006/09/19 23:42:53.36 UTC MINOR: DEBUG #2001 - LDP "LDP: LDP Send Keepalive packet (msgId 3) to 10.10.10.243:0 " 59 2006/09/19 23:42:53.37 UTC MINOR: DEBUG #2001 - LDP "LDP: LDP Send Address packet (msgId 4) to 10.10.10.243:0 Address Family = 1 Number of addresses = 5 Address 1 = 10.3.4.3 Address 2 = 10.2.3.3 Address 3 = 10.1.3.3 Address 4 = 10.48.1.1 Address 5 = 10.10.10.223 " 60 2006/09/19 23:42:53.37 UTC MINOR: DEBUG #2001 - LDP "LDP: LDP Send Label Mapping packet (msgId 5) to 10.10.10.243:0 Label 131071 advertised for the following FECs Address Prefix Address Family = 1 Prefix = 10.10.10.223/32 " 61 2006/09/19 23:42:53.38 UTC MINOR: DEBUG #2001 - LDP "LDP: LDP Recv Address packet (msgId = 4) from 10.10.10.243:0 Address Family = 1 Number of addresses = 2 Address 1 = 10.48.1.2 Address 2 = 10.10.10.243 " 62 2006/09/19 23:42:53.38 UTC MINOR: DEBUG #2001 - LDP "LDP: LDP Recv Label Mapping packet (msgId = 5) from 10.10.10.243:0 Label 131071 advertised for the following FECs Address Prefix Address Family = 1 Prefix = 10.10.10.243/32 "
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Section 3.2 â&#x20AC;&#x201C; Configuring and Verifying the Provider Core for LDP
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Exercise: 1. 2.
Enable LDP on all the interfaces of your P router to the other P routers. (LDP should have already been enabled between your P and PE routers from lab 3.1). Verify that the core IGP and LDP processes are up on your PE & P routers and that LDP has been enabled on all provider core network interfaces. An example of the output is shown below. a. How many LDP neighbors should each P router have? b. How many should each PE router have?
A:P1# show router ldp interface =============================================================================== LDP Interfaces =============================================================================== Interface Adm Opr Hello Hold KA KA Transport Factor Time Factor Timeout Address ------------------------------------------------------------------------------P1-P2 Up Up 3 15 3 30 System P1-P3 Up Up 3 15 3 30 System P1-P4 Up Up 3 15 3 30 System P1-PE1 Up Up 3 15 3 30 System ------------------------------------------------------------------------------No. of Interfaces: 4 ===============================================================================
3.
Verify that the LDP sessions with peer routers are UP. An example of the output is shown below. a. How many LDP sessions does your P router have? b. How many sessions does your PE router have? c. What types of adjacencies are formed? Why?
A:P1# show router ldp session =============================================================================== LDP Sessions =============================================================================== Peer LDP Id Adj Type State Mesg Sent Mesg Recv Up Time ------------------------------------------------------------------------------10.10.10.224:0 Link Established 254 255 0d 00:11:24 10.10.10.223:0 Link Established 250 251 0d 00:11:11 10.10.10.222:0 Link Established 257 256 0d 00:11:35 10.10.10.241:0 Link Established 261 260 0d 00:11:01 ------------------------------------------------------------------------------No. of Sessions: 4 ===============================================================================
4.
Verify the Label Information Base (LIB) of your P and PE routers. An example is shown below. a. How many prefix bindings should be present? Explain. b. Should the P and PE routers have the same number of prefix bindings? c. What is the label generated by your P router for the FEC corresponding to its system address? d. On your P router, what is the label received from the diagonally connected P router for the FEC corresponding to the diagonally connected Podâ&#x20AC;&#x2122;s PE router? e. Why does your P router have some labels that are not in use?
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A:P1# show router ldp bindings
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=============================================================================== LDP LSR ID: 10.10.10.221 =============================================================================== Legend: U - Label In Use, N - Label Not In Use, W - Label Withdrawn S - Status Signaled Up, D - Status Signaled Down E - Epipe Service, V - VPLS Service, M - Mirror Service A - Apipe Service, F - Fpipe Service, I - IES Service, R - VPRN service P - Ipipe Service =============================================================================== LDP Prefix Bindings =============================================================================== Prefix Peer IngLbl EgrLbl EgrIntf EgrNextHop ------------------------------------------------------------------------------10.10.10.221/32 10.10.10.222 131071U ---10.10.10.221/32 10.10.10.223 131071U ---10.10.10.221/32 10.10.10.224 131071U ---10.10.10.221/32 10.10.10.241 131071U ---10.10.10.222/32 10.10.10.222 -131071 1/1/2 10.1.2.2 10.10.10.222/32 10.10.10.223 131070U 131067 --10.10.10.222/32 10.10.10.224 131070U 131068 --10.10.10.222/32 10.10.10.241 131070U 131069 --10.10.10.223/32 10.10.10.222 131067U 131067 --10.10.10.223/32 10.10.10.223 -131071 1/1/4 10.1.3.3 10.10.10.223/32 10.10.10.224 131067U 131067 --10.10.10.223/32 10.10.10.241 131067U 131068 --10.10.10.224/32 10.10.10.222 131065U 131065 --10.10.10.224/32 10.10.10.223 131065U 131065 --10.10.10.224/32 10.10.10.224 -131071 1/1/3 10.1.4.4 10.10.10.224/32 10.10.10.241 131065U 131067 --10.10.10.241/32 10.10.10.222 131063U 131063 --10.10.10.241/32 10.10.10.223 131063U 131063 --10.10.10.241/32 10.10.10.224 131063U 131064 --10.10.10.241/32 10.10.10.241 -131071 1/1/1 10.16.1.2 10.10.10.242/32 10.10.10.222 131068N 131069 1/1/2 10.1.2.2 10.10.10.242/32 10.10.10.223 131068U 131066 --10.10.10.242/32 10.10.10.224 131068U 131066 --10.10.10.242/32 10.10.10.241 131068U 131066 --10.10.10.243/32 10.10.10.222 131066U 131066 --10.10.10.243/32 10.10.10.223 131066N 131070 1/1/4 10.1.3.3 10.10.10.243/32 10.10.10.224 131066U 131065 --10.10.10.243/32 10.10.10.241 131066U 131065 --10.10.10.244/32 10.10.10.222 131064U 131064 --10.10.10.244/32 10.10.10.223 131064U 131064 --10.10.10.244/32 10.10.10.224 131064N 131070 1/1/3 10.1.4.4 10.10.10.244/32 10.10.10.241 131064U 131064 --------------------------------------------------------------------------------No. of Prefix Bindings: 32 =============================================================================== LDP Service Bindings =============================================================================== Type VCId SvcId SDPId Peer IngLbl EgrLbl LMTU RMTU ------------------------------------------------------------------------------No Matching Entries Found ===============================================================================
5.
Verify that the Label Forwarding Information Base (LFIB) of your P and PE routers contains the active labels used by the router for MPLS forwarding. An example is shown below.
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a.
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b. c. d.
What is the difference in the ‘show router ldp bindings’ when the ‘active’ keyword is used? Why are there fewer prefix bindings in the LFIB than the FIB? Why does your P router have both a PUSH and SWAP operation for the prefix corresponding to your PE router? Based on the output of the ‘show router ldp bindings active’ command can you tell the system address of the router on which the command is executed? Identify all the label mappings corresponding to the LSP extending from your PE router to the PE router of the diagonally connected Pod. At each router along the path identify the label that is PUSHed, SWAPed or POPed.
A:P1# show router ldp bindings active =============================================================================== Legend: (S) - Static =============================================================================== LDP Prefix Bindings (Active) =============================================================================== Prefix Op IngLbl EgrLbl EgrIntf EgrNextHop ------------------------------------------------------------------------------10.10.10.221/32 Pop 131071 ---10.10.10.222/32 Push -131071 1/1/2 10.1.2.2 10.10.10.222/32 Swap 131070 131071 1/1/2 10.1.2.2 10.10.10.223/32 Push -131071 1/1/4 10.1.3.3 10.10.10.223/32 Swap 131067 131071 1/1/4 10.1.3.3 10.10.10.224/32 Push -131071 1/1/3 10.1.4.4 10.10.10.224/32 Swap 131065 131071 1/1/3 10.1.4.4 10.10.10.241/32 Push -131071 1/1/1 10.16.1.2 10.10.10.241/32 Swap 131063 131071 1/1/1 10.16.1.2 10.10.10.242/32 Push -131069 1/1/2 10.1.2.2 10.10.10.242/32 Swap 131068 131069 1/1/2 10.1.2.2 10.10.10.243/32 Push -131070 1/1/4 10.1.3.3 10.10.10.243/32 Swap 131066 131070 1/1/4 10.1.3.3 10.10.10.244/32 Push -131070 1/1/3 10.1.4.4 10.10.10.244/32 Swap 131064 131070 1/1/3 10.1.4.4 ------------------------------------------------------------------------------No. of Prefix Bindings: 15 ===============================================================================
6.
Verify the LSPs that are present. An example is shown below. a. What are the FECs for which the LSPs have been created? b. What does the metric value represent?
A:PE1# show router tunnel-table protocol ldp =============================================================================== Tunnel Table (Router: Base) =============================================================================== Destination Owner Encap TunnelId Pref Nexthop Metric ------------------------------------------------------------------------------10.10.10.221/32 ldp MPLS 9 10.16.1.1 300 10.10.10.222/32 ldp MPLS 9 10.16.1.1 100 10.10.10.223/32 ldp MPLS 9 10.16.1.1 200 10.10.10.224/32 ldp MPLS 9 10.16.1.1 200 10.10.10.242/32 ldp MPLS 9 10.16.1.1 300 10.10.10.243/32 ldp MPLS 9 10.16.1.1 200 10.10.10.244/32 ldp MPLS 9 10.16.1.1 200 ===============================================================================
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7. 8.
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On your P router shutdown the interface to your diagonally connected neighbor P router. Verify the Label Information Base (LIB) of your P and PE routers. a. How has the LIB changed on the P and PE router compared to before the interface shutdown? 9. Verify the Label Forwarding Information Base (LFIB) of your P and PE routers. a. How has the LFIB changed on the P and PE router compared to before the interface shutdown? b. What is the LSP path for packets originating on your PE router and destined for your diagonally connected neighbor Pod’s PE router now? c. What label does your P router SWAP in for a packet coming in from your PE router destined for your diagonally connected neighbor Pod’s PE router? 10. Use the oam lsp-trace command to verify the path taken to your diagonal PE router.
Note: Keep the interface from your P router to the diagonally connected P router in the shutdown mode.
Section 3.3 – Enabling ECMP LDP Exercise: 1. 2. 3.
Enable ECMP for 4 equal cost paths. Verify the routing table on your P router. What is the next-hop to reach the PE router in the diagonally connected neighbor Pod? Verify the Label Information Base (LIB) of your P and PE routers. An example is shown below. a. Is there any difference on your P and PE with the output of the LIB without ECMP LDP enabled? b. How many Prefixes bindings should be present in your P and PE router’s LIB? Explain.
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A:P1> # show router ldp bindings
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=============================================================================== LDP LSR ID: 10.10.10.221 =============================================================================== Legend: U - Label In Use, N - Label Not In Use, W - Label Withdrawn S - Status Signaled Up, D - Status Signaled Down E - Epipe Service, V - VPLS Service, M - Mirror Service A - Apipe Service, F - Fpipe Service, I - IES Service, R - VPRN service P - Ipipe Service =============================================================================== LDP Prefix Bindings =============================================================================== Prefix Peer IngLbl EgrLbl EgrIntf EgrNextHop ------------------------------------------------------------------------------10.10.10.221/32 10.10.10.222 131071U ---10.10.10.221/32 10.10.10.223 131071U ---10.10.10.221/32 10.10.10.241 131071U ---10.10.10.222/32 10.10.10.222 -131071 1/1/2 10.1.2.2 10.10.10.222/32 10.10.10.223 131070U 131067 --10.10.10.222/32 10.10.10.241 131070U 131069 --10.10.10.223/32 10.10.10.222 131067U 131067 --10.10.10.223/32 10.10.10.223 -131071 1/1/4 10.1.3.3 10.10.10.223/32 10.10.10.241 131067U 131068 --10.10.10.224/32 10.10.10.222 131065N 131065 1/1/2 10.1.2.2 10.10.10.224/32 10.10.10.223 131065N 131065 1/1/4 10.1.3.3 10.10.10.224/32 10.10.10.241 131065U 131061 --10.10.10.241/32 10.10.10.222 131063U 131063 --10.10.10.241/32 10.10.10.223 131063U 131063 --10.10.10.241/32 10.10.10.241 -131071 1/1/1 10.16.1.2 10.10.10.242/32 10.10.10.222 131068N 131069 1/1/2 10.1.2.2 10.10.10.242/32 10.10.10.223 131068U 131066 --10.10.10.242/32 10.10.10.241 131068U 131066 --10.10.10.243/32 10.10.10.222 131066U 131066 --10.10.10.243/32 10.10.10.223 131066N 131070 1/1/4 10.1.3.3 10.10.10.243/32 10.10.10.241 131066U 131065 --10.10.10.244/32 10.10.10.222 131064N 131064 1/1/2 10.1.2.2 10.10.10.244/32 10.10.10.223 131064N 131064 1/1/4 10.1.3.3 10.10.10.244/32 10.10.10.241 131064U 131060 --------------------------------------------------------------------------------No. of Prefix Bindings: 24
========================================================================== 4.
Verify the Label Forwarding Information Base (LFIB) of your P and PE routers. An example is shown below. a. Is there any difference on your P and PE routers with the output of the LFIB without ECMP LDP enabled? b. How many equal cost LSPs are there from your P router to the PE router in the diagonally connected neighbor Pod?
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A:P1># show router ldp bindings active
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=============================================================================== Legend: (S) - Static =============================================================================== LDP Prefix Bindings (Active) =============================================================================== Prefix Op IngLbl EgrLbl EgrIntf EgrNextHop ------------------------------------------------------------------------------10.10.10.221/32 Pop 131071 ---10.10.10.222/32 Push -131071 1/1/2 10.1.2.2 10.10.10.222/32 Swap 131070 131071 1/1/2 10.1.2.2 10.10.10.223/32 Push -131071 1/1/4 10.1.3.3 10.10.10.223/32 Swap 131067 131071 1/1/4 10.1.3.3 10.10.10.224/32 Push -131065 1/1/2 10.1.2.2 10.10.10.224/32 Swap 131065 131065 1/1/2 10.1.2.2 10.10.10.224/32 Push -131065 1/1/4 10.1.3.3 10.10.10.224/32 Swap 131065 131065 1/1/4 10.1.3.3 10.10.10.241/32 Push -131071 1/1/1 10.16.1.2 10.10.10.241/32 Swap 131063 131071 1/1/1 10.16.1.2 10.10.10.242/32 Push -131069 1/1/2 10.1.2.2 10.10.10.242/32 Swap 131068 131069 1/1/2 10.1.2.2 10.10.10.243/32 Push -131070 1/1/4 10.1.3.3 10.10.10.243/32 Swap 131066 131070 1/1/4 10.1.3.3 10.10.10.244/32 Push -131064 1/1/2 10.1.2.2 10.10.10.244/32 Swap 131064 131064 1/1/2 10.1.2.2 10.10.10.244/32 Push -131064 1/1/4 10.1.3.3 10.10.10.244/32 Swap 131064 131064 1/1/4 10.1.3.3 ------------------------------------------------------------------------------No. of Prefix Bindings: 19 ===============================================================================
5.
Verify the number of LSPs present on your P and PE routers. An example is shown below. a. How many LSPs are there to reach the diagonally connected neighbor Pod’s P and PE routers? b. How many LSPs are there to reach the other routers?
A:P1# show router tunnel-table protocol ldp =============================================================================== Tunnel Table (Router: Base) =============================================================================== Destination Owner Encap TunnelId Pref Nexthop Metric ------------------------------------------------------------------------------10.10.10.222/32 ldp MPLS 9 10.1.2.2 100 10.10.10.223/32 ldp MPLS 9 10.1.3.3 100 10.10.10.224/32 ldp MPLS 9 10.1.2.2 200 10.10.10.224/32 ldp MPLS 9 10.1.3.3 200 10.10.10.241/32 ldp MPLS 9 10.16.1.2 100 10.10.10.242/32 ldp MPLS 9 10.1.2.2 200 10.10.10.243/32 ldp MPLS 9 10.1.3.3 200 10.10.10.244/32 ldp MPLS 9 10.1.2.2 300 10.10.10.244/32 ldp MPLS 9 10.1.3.3 300 ===============================================================================
6. 7.
From your P router do a LSP trace to the diagonally connected neighbor P router’s system address. Which LSP is used? From your P router do a LSP trace to the diagonally connected neighbor PE router system address. Which LSP is used?
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8.
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From your PE router do a LSP trace to the diagonally connected neighbor P router system address. Which LSP is used? 9. From your PE router do a LSP trace to the diagonally connected neighbor PE router system address. Which LSP is used? 10. Re-enable the interface from your P router to your diagonally connected neighbor P router by executing a ‘no shutdown’ command.
Section 3.4 – Applying Export Policy for Label Distribution Exercise: 1.
Configure an Export policy with a single entry set to “action accept”. An example is shown below.
-------------------------------------------------echo "Policy Configuration" #-------------------------------------------------policy-options begin policy-statement "ldp-export" entry 10 action accept exit exit exit commit exit exit
2. 3.
Apply the Export policy to LDP on your PE and P router. Verify the Label Information Base (LIB) of your P and PE routers. An example is shown below. a. For what additional FEC are labels now generated? b. How many Prefix bindings should be present? Explain.
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A:PE1# show router ldp bindings
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=============================================================================== LDP LSR ID: 10.10.10.241 =============================================================================== Legend: U - Label In Use, N - Label Not In Use, W - Label Withdrawn S - Status Signaled Up, D - Status Signaled Down E - Epipe Service, V - VPLS Service, M - Mirror Service A - Apipe Service, F - Fpipe Service, I - IES Service, R - VPRN service P - Ipipe Service =============================================================================== LDP Prefix Bindings =============================================================================== Prefix Peer IngLbl EgrLbl EgrIntf EgrNextHop ------------------------------------------------------------------------------10.1.2.0/24 10.10.10.221 131067N 131069 1/2/1 10.16.1.1 10.1.3.0/24 10.10.10.221 131064N 131061 1/2/1 10.16.1.1 10.1.4.0/24 10.10.10.221 131053N 131051 1/2/1 10.16.1.1 10.2.3.0/24 10.10.10.221 131059N 131058 1/2/1 10.16.1.1 10.2.4.0/24 10.10.10.221 131058N 131057 1/2/1 10.16.1.1 10.3.4.0/24 10.10.10.221 131057N 131055 1/2/1 10.16.1.1 10.10.10.221/32 10.10.10.221 -131071 1/2/1 10.16.1.1 10.10.10.222/32 10.10.10.221 131069N 131070 1/2/1 10.16.1.1 10.10.10.223/32 10.10.10.221 131068N 131067 1/2/1 10.16.1.1 10.10.10.224/32 10.10.10.221 131061N 131065 1/2/1 10.16.1.1 10.10.10.241/32 10.10.10.221 131071U ---10.10.10.242/32 10.10.10.221 131066N 131068 1/2/1 10.16.1.1 10.10.10.243/32 10.10.10.221 131065N 131066 1/2/1 10.16.1.1 10.10.10.244/32 10.10.10.221 131060N 131064 1/2/1 10.16.1.1 10.16.1.0/24 10.10.10.221 131063U 131060 --10.32.1.0/24 10.10.10.221 131062N 131059 1/2/1 10.16.1.1 10.48.1.0/24 10.10.10.221 131056N 131054 1/2/1 10.16.1.1 10.64.1.0/24 10.10.10.221 131052N 131050 1/2/1 10.16.1.1 ------------------------------------------------------------------------------No. of Prefix Bindings: 18 =============================================================================== LDP Service Bindings =============================================================================== Type VCId SvcId SDPId Peer IngLbl EgrLbl LMTU RMTU ------------------------------------------------------------------------------No Matching Entries Found ============================================================================
4.
Verify that the Label Forwarding Information Base (LFIB) of your P and PE routers contains the active labels used by the router for MPLS forwarding. An example is shown below.
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A:P1# show router ldp bindings active
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=============================================================================== Legend: (S) - Static =============================================================================== LDP Prefix Bindings (Active) =============================================================================== Prefix Op IngLbl EgrLbl EgrIntf EgrNextHop ------------------------------------------------------------------------------10.1.2.0/24 Pop 131069 ---10.1.3.0/24 Pop 131061 ---10.2.4.0/24 Swap 131057 131057 1/1/2 10.1.2.2 10.3.4.0/24 Swap 131055 131053 1/1/4 10.1.3.3 10.10.10.221/32 Pop 131071 ---10.10.10.222/32 Push -131071 1/1/2 10.1.2.2 10.10.10.222/32 Swap 131070 131071 1/1/2 10.1.2.2 10.10.10.223/32 Push -131071 1/1/4 10.1.3.3 10.10.10.223/32 Swap 131067 131071 1/1/4 10.1.3.3 10.10.10.224/32 Push -131065 1/1/4 10.1.3.3 10.10.10.224/32 Swap 131065 131065 1/1/4 10.1.3.3 10.10.10.241/32 Push -131071 1/1/1 10.16.1.2 10.10.10.241/32 Swap 131063 131071 1/1/1 10.16.1.2 10.10.10.242/32 Push -131069 1/1/2 10.1.2.2 10.10.10.242/32 Swap 131068 131069 1/1/2 10.1.2.2 10.10.10.243/32 Push -131070 1/1/4 10.1.3.3 10.10.10.243/32 Swap 131066 131070 1/1/4 10.1.3.3 10.10.10.244/32 Push -131064 1/1/4 10.1.3.3 10.10.10.244/32 Swap 131064 131064 1/1/4 10.1.3.3 10.16.1.0/24 Pop 131060 ---10.32.1.0/24 Swap 131059 131059 1/1/2 10.1.2.2 10.48.1.0/24 Swap 131054 131054 1/1/4 10.1.3.3 10.64.1.0/24 Swap 131050 131049 1/1/4 10.1.3.3 ------------------------------------------------------------------------------No. of Prefix Bindings: 23 ===============================================================================
Section 3.5 â&#x20AC;&#x201C; Configuring Targeted LDP Exercise: 1. 2. 3.
On your PE router configure Targeted LDP sessions with every other PE router and with your P router. On your P router configure a Targeted LDP session with your PE router. Verify that the LDP Targeted sessions are operational. An example is shown below. a. What adjacency types are established between the PE routers? Why? b. What adjacency type is established between your PE and P routers? Why?
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A:PE1# show router ldp session
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=============================================================================== LDP Sessions =============================================================================== Peer LDP Id Adj Type State Mesg Sent Mesg Recv Up Time ------------------------------------------------------------------------------10.10.10.221:0 Both Established 258 257 0d 00:10:48 10.10.10.242:0 Targeted Established 434 431 0d 01:42:14 10.10.10.243:0 Targeted Established 273 275 0d 00:24:44 10.10.10.244:0 Targeted Established 12777 12778 0d 19:26:17 ------------------------------------------------------------------------------No. of Sessions: 4 ===============================================================================
4.
On your PE and P router verify that both interface based LDP and targeted LDP are enabled. An example is shown below. a. How many direct and targeted LDP peers do your PE and P routers have? b. What are the FECs sent by your PE and P routers? c. What are the FECs received by your PE and P routers?
A:P1# show router ldp status =============================================================================== LDP Status for LSR ID 10.10.10.221 =============================================================================== Admin State : Up Oper State : Up Created at : 09/13/2006 15:49:31 Up Time : 0d 20:10:10 Oper Down Reason : n/a Oper Down Events : 0 Last Change : 09/13/2006 19:19:10 Tunn Down Damp Time : 3 sec Import Policies : None Export Policies : None Active Adjacencies : 5 Active Sessions : 4 Active Interfaces : 4 Inactive Interfaces : 0 Active Peers : 1 Inactive Peers : 0 Addr FECs Sent : 24 Addr FECs Recv : 24 Serv FECs Sent : 0 Serv FECs Recv : 0 Attempted Sessions : 0 No Hello Err : 0 Param Adv Err : 0 Max PDU Err : 0 Label Range Err : 0 Bad LDP Id Err : 0 Bad PDU Len Err : 0 Bad Mesg Len Err : 0 Bad TLV Len Err : 0 Malformed TLV Err : 0 Keepalive Expired Err: 0 Shutdown Notif Sent: 0 Shutdown Notif Recv : 1 ===============================================================================
5.
Verify that the MPLS label exchange has not been impacted by the change in LDP by using the ‘show router ldp bindings [active] command. Compare the output to that shown in Section 3-2 to ensure they are the same.
Note: After having configured Targeted LDP in this lab you will notice that no additional labels appear in the output of the ‘show router ldp bindings’ command. In other words, the T-LDP peers have not exchanged any label bindings over their Targeted LDP session. This is normal behavior. The T-LDP peers will only generate and exchange labels after VLL or VPLS services are configured between them.
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Lab 3 Review Questions
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1. 2. 3. 4.
Which command may be used to view the details of each LDP peer? Is it possible for two routers to form both a link and targeted LDP adjacency? For which FECs are labels advertised by default? How can additional FECs be advertised? How does a router determine which LSP to use when ECMP LDP is enabled?
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Lab 4
Enabling Provider Core OSPF-TE and MPLS
Objective: The purpose of this lab is to enable MPLS and Traffic Engineering extensions on the OSPF routing protocol in the service provider network and verify the Traffic Engineering Database.
MPLS/RSVP
Service Provider Network LDP Enabled Core
Edge 1
10.16.1.0/24
Edge 2
10.32.1.0/24
Pod 1
Pod 2 Core 1
Core 2 10.x.y.z/24
Core 3
Core 4
Pod 3 10.48.1.0/24
Pod 4
10.64.1.0/24
Edge 4
Edge 3
Figure 4-1: Enabling Provider Core MPLS
Syntax: The configuration and verification commands required for this Lab are provided in Table 4-1. Refer to the student guide for additional command details. Each command may have additional parameters possible. Use the â&#x20AC;&#x2DC;?â&#x20AC;&#x2122; character for help and to explore all command line options. Other commands may also be used, including those found in previous exercises and courses.
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Lab 4 Command List #configure router ospf traffic-engineering #configure router mpls interface <interface-name> #show router ospf status #show router ospf opaque-database #show router ospf opaque-database adv-router <router-id> detail #show router ospf area detail info (from all contexts) exit [all] (from all contexts) #admin save
Table 4-1 Lab 4 Configuration and Verification Commands
Exercise: 1. 2.
3.
On your P and PE routers use the “show router status” command to verify that MPLS has not been configured (i.e. the administrative and operational status of MPLS is “Not configured”). On your P and PE routers, use the “show router ospf status” command to verify that currently Traffic Engineering is disabled. a. Are Opaque LSAs supported on your P/PE router? b. What does it mean if a router supports Opaque LSAs but TE support is disabled? On your P router view the opaque database to verify that currently the router does not see any opaque LSAs. An example of the output is shown below.
Note: If others in the class have already enabled TE, your router may see some Opaque LSAs but they are not being generated by your router since you have not yet enabled TE. A:P1# show router ospf opaque-database =============================================================================== OSPF Opaque Link State Database (Type : All) =============================================================================== Type Id Link State Id Adv Rtr Id Age Sequence Cksum ------------------------------------------------------------------------------------------------------------------------------------------------------------No. of Opaque LSAs: 0 =============================================================================== A:P1#
4.
On your P router view the number of Type 10 Area Opaque LSAs. An example of the output is shown below. a. How many Type 10 LSAs are being reported? b. What could be an explanation if at this point prior to enabling Traffic Engineering on your router, the number of Type 10 LSAs is not 0?
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AA:P1# show router ospf area detail
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=============================================================================== OSPF Areas (Detailed) =============================================================================== ------------------------------------------------------------------------------Area Id: 0.0.0.0 ------------------------------------------------------------------------------Area Id : 0.0.0.0 Type : Standard Virtual Links : 0 Total Nbrs : 4 Active IFs : 5 Total IFs : 5 Area Bdr Rtrs : 0 AS Bdr Rtrs : 0 SPF Runs : 73 Last SPF Run : 09/14/2006 11:15:27 Router LSAs : 8 Network LSAs : 9 Summary LSAs : 0 Asbr-summ LSAs : 0 Nssa ext LSAs : 0 Area opaque LSAs : 0 Total LSAs : 17 LSA Cksum Sum : 0x138e83 Blackhole Range : True Unknown LSAs : 0 ===============================================================================
5. 6.
For now enable Traffic Engineering only on your PE router. Now on your P router again view the number of Type 10 Area Opaque LSAs. An example output is shown below. a. How many Type 10 LSAs do you see? b. Why has this value increased even though you have not enabled TE on this router? A:P1# show router ospf area detail =============================================================================== OSPF Areas (Detailed) =============================================================================== ------------------------------------------------------------------------------Area Id: 0.0.0.0 ------------------------------------------------------------------------------Area Id : 0.0.0.0 Type : Standard Virtual Links : 0 Active IFs : 5 Area Bdr Rtrs : 0 AS Bdr Rtrs : 0 SPF Runs : 14 Last SPF Run : 02/02/2002 18:05:05 Router LSAs : 8 Network LSAs : 9 Summary LSAs : 0 Asbr-summ LSAs : 0 Nssa ext LSAs : 0 Area opaque LSAs : 1 Total LSAs : 25 LSA Cksum Sum : 0xc531b Blackhole Range : True =============================================================================== A:P1#
7. 8. 9.
Now enable Traffic Engineering on your P router. Confirm that now Traffic Engineering is now enabled On your P router verify that the router now has opaque routes in the database. An example output is shown below.
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A:P1# show router ospf opaque-database
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=============================================================================== OSPF Opaque Link State Database (Type : All) =============================================================================== Type Id Link State Id Adv Rtr Id Age Sequence Cksum ------------------------------------------------------------------------------Area 0.0.0.0 1.0.0.1 10.10.10.75 60 0x80000001 0x3b41 Area 0.0.0.0 1.0.0.1 10.10.10.76 65 0x80000001 0x3f3b Area 0.0.0.0 1.0.0.1 10.10.10.77 36 0x80000001 0x4335 Area 0.0.0.0 1.0.0.1 10.10.10.78 41 0x80000001 0x472f Area 0.0.0.0 1.0.0.1 10.10.10.79 49 0x80000001 0x4b29 Area 0.0.0.0 1.0.0.1 10.10.10.80 46 0x80000001 0x4f23 Area 0.0.0.0 1.0.0.1 10.10.10.81 25 0x80000001 0x531d Area 0.0.0.0 1.0.0.1 10.10.10.82 19 0x80000001 0x5717 ------------------------------------------------------------------------------No. of Opaque LSAs: 8 =============================================================================== A:P1#
10. On your P router use the “show router ospf opaque-database adv-router <router-id> detail” command, where <router-id> is the router ID of your P router, to view a more detailed description of the opaque LSA for your router. An example output is shown below. a. What is the LSA type number for “Area Opaque”? b. Why does the Area ID show up as 0.0.0.0? c. Which top-level TLV sub-type does the LSA contain, and what does it specify? A:P1# show router ospf opaque-database adv-router 10.10.10.221 detail =============================================================================== OSPF Opaque Link State Database (Type : All) (Detailed) =============================================================================== ------------------------------------------------------------------------------Opaque LSA ------------------------------------------------------------------------------Area Id : 0.0.0.0 Adv Router Id : 10.10.10.221 Link State Id : 1.0.0.1 LSA Type : Area Opaque Sequence No : 0x80000001 Checksum : 0x3b41 Age : 221 Length : 28 Options : E Advertisement : ROUTER-ID TLV (0001) Len 4 : 10.10.10.221 ===============================================================================
11. Again verify the number of Type 10 Area Opaque LSAs now discovered. An example output is shown below. a. Write down the number of Type 10 LSAs now being reported. b. How many Type 10 LSAs should be discovered when everyone in the class has finished enabling Traffic Engineering?
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A:P1# show router ospf area detail
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=============================================================================== OSPF Areas (Detailed) =============================================================================== ------------------------------------------------------------------------------Area Id: 0.0.0.0 ------------------------------------------------------------------------------Area Id : 0.0.0.0 Type : Standard Virtual Links : 0 Active IFs : 5 Area Bdr Rtrs : 0 AS Bdr Rtrs : 0 SPF Runs : 14 Last SPF Run : 02/02/2002 18:05:05 Type 1 LSAs : 8 Type 2 LSAs : 9 Type 3 LSAs : 0 Type 4 LSAs : 0 Type 7 LSAs : 0 Type 10 LSAs : 8 Total LSAs : 25 LSA Cksum Sum : 0xc531b Blackhole Range : True =============================================================================== A:P1#
12. Enable MPLS for all interfaces on your P and PE routers, including your system interfaces. 13. Verify that MPLS has been enabled for your interfaces and that the relevant interfaces are administratively and operationally “up”. An example output is shown below.
A:P1# show router mpls interface =============================================================================== MPLS Interfaces =============================================================================== Interface Port-id Adm Opr ------------------------------------------------------------------------------system system Up Up Admin Groups None P1-PE1 1/1/1 Up Up Admin Groups None P1-P2 1/1/2 Up Up Admin Groups None P1-P3 1/1/3 Up Up Admin Groups None P1-P4 1/1/4 Up Up Admin Groups None ------------------------------------------------------------------------------Interfaces : 5 =============================================================================== A:P1#
14. On your P router again use the “show router ospf opaque-database adv-router <router-id> detail” command, where <router-id> is the router ID of your P router, to view a more detailed description of the opaque LSA for your router. An example output is shown below. a. How many opaque LSAs does your P router have in its opaque-database? b. The LSAs contain which additional top-level TLV sub-type? What does this LSA specify?
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A:PE1# show router ospf opaque-database adv-router 10.10.10.241 detail
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=============================================================================== OSPF Opaque Link State Database (Type : All) (Detailed) =============================================================================== ------------------------------------------------------------------------------Opaque LSA ------------------------------------------------------------------------------Area Id : 0.0.0.0 Adv Router Id : 10.10.10.241 Link State Id : 1.0.0.1 LSA Type : Area Opaque Sequence No : 0x80000001 Checksum : 0xd559 Age : 10 Length : 28 Options : E Advertisement : ROUTER-ID TLV (0001) Len 4 : 10.10.10.241 ------------------------------------------------------------------------------Opaque LSA ------------------------------------------------------------------------------Area Id : 0.0.0.0 Adv Router Id : 10.10.10.241 Link State Id : 1.0.0.2 LSA Type : Area Opaque Sequence No : 0x80000001 Checksum : 0x2e2f Age : 10 Length : 124 Options : E Advertisement : LINK INFO TLV (0002) Len 100 : Sub-TLV: 1 Len: 1 LINK_TYPE : 2 Sub-TLV: 2 Len: 4 LINK_ID : 10.16.1.2 Sub-TLV: 3 Len: 4 LOC_IP_ADDR : 10.16.1.2 Sub-TLV: 4 Len: 4 REM_IP_ADDR : 0.0.0.0 Sub-TLV: 5 Len: 4 TE_METRIC : 100 Sub-TLV: 6 Len: 4 MAX_BDWTH : 1000000 Kbps Sub-TLV: 7 Len: 4 RSRVBL_BDWTH : 1000000 Kbps Sub-TLV: 8 Len: 32 UNRSRVD_CLS0 : P0: 1000000 Kbps P1: 1000000 Kbps P2: 1000000 Kbps P3: 1000000 Kbps P4: 1000000 Kbps P5: 1000000 Kbps P6: 1000000 Kbps P7: 1000000 Kbps Sub-TLV: 9 Len: 4 ADMIN_GROUP : 0 None ===========================================================================
Lab 4 Review Questions 1. 2. 3. 4. 5.
Why must Traffic Engineering extensions be enabled on OSPF? What additional information is advertised by the routers when Traffic Engineering is enabled on OSPF? What type of LSA is used to carry this additional information and where is it stored? What happens to the LSA type used for TE extensions in a multi-area OSPF network? What is missing in the opaque database if MPLS has not been enabled on the routersâ&#x20AC;&#x2122; interfaces?
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Lab 5
CSPF Based LSPs and LSP Establishment
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Objective: The purpose of this lab is to: • Establish LSPs using RSVP-TE signaling, with and without constraints, and to observe the path determined for the LSPs. • View the RSVP messages exchanged during LSP establishment. LSPs from P-P
Service Provider Network RSVP-TE Enabled Core
Edge 1
10.16.1.0/24
Edge 2
10.32.1.0/24
Pod 1
Pod 2 Core 1
Core 2 10.x.y.z/24
Core 3
Core 4
Pod 3 10.48.1.0/24
Pod 4
10.64.1.0/24
Edge 4
Edge 3 LSPs from PE-PE
Figure 5-1: CSPF Based LSPs
Syntax: The configuration and verification commands required for this Lab are provided in Table 5-1. Refer to the student guide for additional command details. Each command may have additional parameters possible. Use the ‘?’ character for help and to explore all command line options. Other commands may also be used, including those found in previous exercises and courses.
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Lab 5 Command List #configure router mpls admin-group <group-name> <group-value> #configure router mpls path <path-name> #configure router mpls path <path-name> hop <index> [strict | loose] #configure router mpls lsp <lsp-name> #configure router mpls lsp <lsp-name> to <system-id> #configure router mpls lsp <lsp-name> cspf #configure router mpls lsp <lsp-name> primary <path-name> #configure router mpls lsp <lsp-name> rsvp-resv-style [se | ff] #configure log log-id <log-id value> #show router mpls path #show router mpls lsp [detail] #show router mpls lsp <lsp-name> path detail #show router mpls admin-group #show router ospf opaque-database [detail] #show router ospf opaque-database adv-router <router-id> detail #show router ospf area detail #show router rsvp session #show router rsvp interface detail #tools perform router mpls cspf to <ip-address> [from <ip-addr>] [bandwidth <bandwidth>] [include-bitmap <bitmap>] [exclude-bitmap <bitmap>] [hop-limit <limit>] [exclude-address <excl-addr> [<excl-addr>...(upto 8 max)]] #debug router rsvp lsp <lsp-name:: path-name> packet path detail #debug router rsvp lsp <lsp-name:: path-name> packet resv detail #debug router rsvp tunnel-id <tunnel-id> lsp-id <lsp-id> packet path detail #debug router rsvp tunnel-id <tunnel-id> lsp-id <lsp-id> packet resv detail #no debug info (from all contexts) exit [all] (from all contexts) #admin save
Table 5-1: Lab 5 Configuration and Verification Commands
Section 5.1â&#x20AC;&#x201C; RSVP-TE LSP Establishment
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Exercise:
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1.
On your PE and P routers configure a log to capture the RSVP-TE packets exchanged during establishment of a LSP using debug-trace (refer to section 3.1 for how to configure the log-id). 2. On your P and PE router configure a path called “loose” and make it totally loose (i.e. do not specify any hops). 3. On your PE router, configure a LSP to your P router, using the path you previously configured. 4. On your P router, configure a LSP to your PE router, using the path you previously configured. 5. Verify that the LSPs on each router is operational. 6. Use the ‘show router rsvp session’ command to obtain the full name of the LSP you configured. The full name of the LSP has the format: lsp-name::path-name. Note also the Tunnel ID and LSP-ID of the LSP. 7. On your PE/P router shutdown the LSP you just configured to your P/PE router. 8. On your PE and P routers enable debug on their respective LSP (which you just shutdown). Enable packet debug on either the full name of the LSP, or on the Tunnel ID and LSP-ID which you previously noted down. Enable packet debug for PATH and RESV packets and use the ‘detail’ keyword to obtain more info. 9. On your PE/P router do a ‘no shutdown’ on the respective LSP you shutdown previously. 10. Observe the PATH and RESV messages transmitted and received on your PE and P routers. An example output is given below. a. For the PATH messages what is the source and destination of the message? b. For the RESV messages what is the source and destination of the message? c. Why is there an ERO object in the PATH message even though the path used is “totally loose”? d. Why does the RRO object in the PATH message only contain one entry? e. Identify the labels that are PUSHed, SWAPed and POPed for packets traveling along this LSP. f. Does the LSP have a high priority for bumping other LSPs? 11. Optional. You can repeat the above steps, using a path with some strict or loose hops specified (instead of a fully loose path). You will notice that the PATH and RESV messages will now contain an ERO object. 14 2007/11/30 20:30:09.79 UTC MINOR: DEBUG #2001 ": PKT Tx : PATH 1.1.1.1 -> 2.2.2.2 Header : Flags 0 Ttl 255 Length 144 Session : End point 2.2.2.2 tid 4 Xtid 1.1.1.1 Hop : Phop 10.1.2.1 Lih 8(toPE2) Time : 30 secs SessAttribute : Name toPE2::dynamic Setup 7 Hold 0 flags 6 SenderTemplate : Sender 1.1.1.1 LspId 4 LabelRequest : L3PID 800 RRO : -> Prefix 10.1.2.1 Flags: -> Label 131070 Flags: Global Label(0x1) Tspec : Qos 1 pdr 73786976294838 pbs 0 cdr 0 cbs 0 mpu 20 mtu 9198 " 15 2007/11/30 20:30:21.40 UTC MINOR: DEBUG #2001 - Session:2.2.2.2_4 "Session:2.2.2.2_4: PKT Rx : RESV 10.1.2.2 -> 10.1.2.1 Header : Flags 0 Ttl 255 Length 128 Session : End point 2.2.2.2 tid 4 Xtid 1.1.1.1 Hop : Phop 10.1.2.2 Lih 8(toPE2) Time : 30 secs Style : SE FlowSpec : qos 1 pdr 73786976294838 pbs 0 cdr 0 cbs 0 mpu 20 mtu 9198 FilterSpec : Sender 1.1.1.1 LspId 4 Label : 131070 RRO : -> Prefix 10.1.2.2 Flags: -> Label 131070 Flags: Global Label(0x1) "
12. Disable debug on your PE and P routers. Alcatel Multiprotocol Label Switching (MPLS) Lab Guide v1.1
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Section 5.2– Configuring CSPF Based LSPs Exercise: 1. 2. 3. 4.
Remove all static LSPs that might be left over from Lab 2. On your PE and P routers look at the opaque-database and note the age of the LSAs corresponding to every link in the network. On your P and PE routers configure an administrative group called “xlink” with a group-value of ‘0’. On your P router only, apply it to the MPLS interface going to the diagonally connected P router. Verify that the admin group has been created on your PE and P routers. Verify that the admin group has been applied to the correct interface on your P router. An example output is shown below.
A:P3# show router mpls admin-group ================================================= MPLS Administrative Groups ================================================= Group Name Group Value ------------------------------------------------xlink 1 ------------------------------------------------No. of Groups: 1 =================================================
A:P3# show router mpls interface =============================================================================== MPLS Interfaces =============================================================================== Interface Port-id Adm Opr ------------------------------------------------------------------------------system system Up Up Admin Groups None P3-PE3 1/2/1 Up Up Admin Groups None P3-P1 1/2/2 Up Up Admin Groups None P3-P2 1/2/3 Up Up Admin Groups xlink P3-P4 1/2/4 Up Up Admin Groups None ------------------------------------------------------------------------------Interfaces : 5 ===============================================================================
5.
On your P router configure the following two LSPs to the diagonally connected P router (for easy identification of the different LSPs use the following naming convention “toPx-lsp#”, where x corresponds to the Pod number and # to the LSP number. In the case of PE routers use “toPEx-lsp#”). DO NOT ENABLE CSPF:
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a.
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6.
7.
8.
9.
LSP1 using the “loose” path configured in the previous lab with bandwidth of 425Mbps using FF reservation style. b. LSP2 using the “loose” path configured in the previous lab excluding the admin-group “xlink” (no bandwidth assigned and using SE reservation style which are the defaults). On your PE router configure the following two LSPs to the PE router in the diagonally connected Pod (for easy identification of the different LSPs use the following naming convention “toPx-lsp#”, where x corresponds to the Pod number and # to the LSP number. In the case of PE routers use “toPEx-lsp#”). DO NOT ENABLE CSPF: a. LSP1 using the “loose” path previously configured with bandwidth of 425Mbps using SE reservation style (this is the default). b. LSP2 using the “loose” path previously configured excluding the admin-group “xlink” (no bandwidth assigned and using SE reservation style which are the defaults). On your P router configure the following LSP to the diagonally connected P router. DO NOT ENABLE CSPF. a. LSP3 using the “loose” path previously configured with bandwidth of 300Mbps and SE reservation style (this is the default). On your PE router configure the following LSP to the PE router in the diagonally connected Pod. DO NOT ENABLE CSPF. a. LSP3 using the “loose” path previously configured with bandwidth of 300Mbps and SE reservation style (this is the default). On your PE and P routers verify the paths taken by the three LSPs configured. An example output is shown below. a. What path does each LSP take? How come? b. Why is LSP #3 down?
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A:PE3# show router mpls lsp path detail
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=============================================================================== MPLS LSP Path (Detail) =============================================================================== Legend : @ - Detour Available # - Detour In Use b - Bandwidth Protected n - Node Protected =============================================================================== ------------------------------------------------------------------------------LSP toPE2-lsp1 Path loose ------------------------------------------------------------------------------LSP Name : to-PE2 Path LSP ID : 6 From : 10.10.10.243 To : 10.10.10.242 Adm State : Up Oper State : Up Path Name : loose Path Type : Primary Path Admin : Up Path Oper : Up OutInterface: 1/2/1 Out Label : 131070 Path Up Time: 0d 00:00:30 Path Dn Time : 0d 00:00:00 Retry Limit : 0 Retry Timer : 30 sec RetryAttempt: 0 Next Retry In : 0 sec Bandwidth : 425 Mbps Oper Bandwidth : 425 Mbps Hop Limit : 255 Record Route: Record Record Label : Record Oper MTU : 9198 Negotiated MTU : 9198 Adaptive : Enabled MBB State : Success Include Grps: Exclude Grps : None None Path Trans : 2 CSPF Queries : 2 Failure Code: noError Failure Node : n/a ExplicitHops: No Hops Specified Actual Hops : 10.48.1.2(10.10.10.243) -> 10.48.1.1(10.10.10.223) Record Label : 131070 -> 10.2.3.2(10.10.10.222) Record Label : 131068 -> 10.32.1.2(10.10.10.242) Record Label : 131070 ComputedHops: 10.48.1.2 -> 10.48.1.1 -> 10.2.3.2 -> 10.32.1.2 ===============================================================================
10. Now enable CSPF on each LSP on your PE and P routers, starting with LSP1, then LSP2 then LSP3 and verify the path taken by each LSP. a. What path does each LSP take now? Why? 11. On your PE & P routers verify the bandwidth reserved on all the MPLS interfaces. An example output is shown. a. What is the reserved bandwidth on the PE router’s interface to P? What is the reserved bandwidth on the P router’s interface to the PE? How can the sum of the two exceed 1Gbps?
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A:P3# show router rsvp interface detail
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=============================================================================== RSVP Interfaces (Detailed) =============================================================================== ------------------------------------------------------------------------------Interface : system ------------------------------------------------------------------------------Interface : system Port ID : system Admin State : Up Oper State : Up Active Sessions: 0 Active Resvs : 0 Total Sessions : 0 Subscription : 100 % Port Speed : 100 Mbps Unreserved BW : 100 Mbps Reserved BW : 0 Mbps Total BW : 100 Mbps Aggregate : Dsabl Hello Interval : 3000 ms Hello Timeouts : 0 No Neighbors. ------------------------------------------------------------------------------Interface : P3-PE3 ------------------------------------------------------------------------------Interface : P3-PE3 Port ID : 1/2/1 Admin State : Up Oper State : Up Active Sessions: 3 Active Resvs : 2 Total Sessions : 3 Subscription : 100 % Port Speed : 1000 Mbps Unreserved BW : 375 Mbps Reserved BW : 725 Mbps Total BW : 1000 Mbps Aggregate : Dsabl Hello Interval : 3000 ms Hello Timeouts : 0 Neighbors : 10.48.1.2 ------------------------------------------------------------------------------Interface : P3-P1 ------------------------------------------------------------------------------Interface : P3-P1 Port ID : 1/2/2 Admin State : Up Oper State : Up Active Sessions: 0 Active Resvs : 0 Total Sessions : 0 Subscription : 100 % Port Speed : 1000 Mbps Unreserved BW : 1000 Mbps Reserved BW : 0 Mbps Total BW : 1000 Mbps Aggregate : Dsabl Hello Interval : 3000 ms Hello Timeouts : 0 Neighbors : 10.1.3.1 ------------------------------------------------------------------------------Interface : P3-P2 ------------------------------------------------------------------------------Interface : P3-P2 Port ID : 1/2/3 Admin State : Up Oper State : Up Active Sessions: 2 Active Resvs : 2 Total Sessions : 2 Subscription : 100 % Port Speed : 1000 Mbps Unreserved BW : 150 Mbps Reserved BW : 850 Mbps Total BW : 1000 Mbps Aggregate : Dsabl Hello Interval : 3000 ms Hello Timeouts : 0 Neighbors : 10.2.3.2 ---end of output omitted----
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12. On your PE & P routers look at the opaque-database and verify that new LSAs were advertised following the establishment of the LSPs with bandwidth reservation and view the bandwidth advertised for each link. An example output is shown below.
A:PE3# show router ospf opaque-database detail -----output omitted------=============================================================================== OSPF Opaque Link State Database (Type : All) (Detailed) ------------------------------------------------------------------------------Opaque LSA ------------------------------------------------------------------------------Area Id : 0.0.0.0 Adv Router Id : 10.10.10.222 Link State Id : 1.0.0.2 LSA Type : Area Opaque Sequence No : 0x8000001b Checksum : 0x7868 Age : 106 Length : 124 Options : E Advertisement : LINK INFO TLV (0002) Len 100 : Sub-TLV: 1 Len: 1 LINK_TYPE : 2 Sub-TLV: 2 Len: 4 LINK_ID : 10.1.2.2 Sub-TLV: 3 Len: 4 LOC_IP_ADDR : 10.1.2.2 Sub-TLV: 4 Len: 4 REM_IP_ADDR : 0.0.0.0 Sub-TLV: 5 Len: 4 TE_METRIC : 100 Sub-TLV: 6 Len: 4 MAX_BDWTH : 1000000 Kbps Sub-TLV: 7 Len: 4 RSRVBL_BDWTH : 1000000 Kbps Sub-TLV: 8 Len: 32 UNRSRVD_CLS0 : P0: 600000 Kbps P1: 600000 Kbps P2: 600000 Kbps P3: 600000 Kbps P4: 600000 Kbps P5: 600000 Kbps P6: 600000 Kbps P7: 600000 Kbps Sub-TLV: 9 Len: 4 ADMIN_GROUP : 0 None ------------------------------------------------------------------------------Opaque LSA ------------------------------------------------------------------------------Area Id : 0.0.0.0 Adv Router Id : 10.10.10.221 Link State Id : 1.0.0.2 LSA Type : Area Opaque Sequence No : 0x8000000f Checksum : 0xcbb4 Age : 1371 Length : 124 Options : E Advertisement : LINK INFO TLV (0002) Len 100 : Sub-TLV: 1 Len: 1 LINK_TYPE : 2 Sub-TLV: 2 Len: 4 LINK_ID : 10.1.2.2 Sub-TLV: 3 Len: 4 LOC_IP_ADDR : 10.1.2.1 Sub-TLV: 4 Len: 4 REM_IP_ADDR : 0.0.0.0 Sub-TLV: 5 Len: 4 TE_METRIC : 100 Sub-TLV: 6 Len: 4 MAX_BDWTH : 1000000 Kbps Sub-TLV: 7 Len: 4 RSRVBL_BDWTH : 1000000 Kbps Sub-TLV: 8 Len: 32 UNRSRVD_CLS0 : P0: 1000000 Kbps P1: 1000000 Kbps P2: 1000000 Kbps P3: 1000000 Kbps P4: 1000000 Kbps P5: 1000000 Kbps P6: 1000000 Kbps P7: 1000000 Kbps Sub-TLV: 9 Len: 4 ADMIN_GROUP : 0 None -----output continued on next page-----
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A:PE3# show router ospf opaque-database detail ------------------------------------------------------------------------------Opaque LSA ------------------------------------------------------------------------------Area Id : 0.0.0.0 Adv Router Id : 10.10.10.223 Link State Id : 1.0.0.3 LSA Type : Area Opaque Sequence No : 0x80000023 Checksum : 0x23b4 Age : 420 Length : 124 Options : E Advertisement : LINK INFO TLV (0002) Len 100 : Sub-TLV: 1 Len: 1 LINK_TYPE : 2 Sub-TLV: 2 Len: 4 LINK_ID : 10.2.3.2 Sub-TLV: 3 Len: 4 LOC_IP_ADDR : 10.2.3.3 Sub-TLV: 4 Len: 4 REM_IP_ADDR : 0.0.0.0 Sub-TLV: 5 Len: 4 TE_METRIC : 100 Sub-TLV: 6 Len: 4 MAX_BDWTH : 1000000 Kbps Sub-TLV: 7 Len: 4 RSRVBL_BDWTH : 1000000 Kbps Sub-TLV: 8 Len: 32 UNRSRVD_CLS0 : P0: 150000 Kbps P1: 150000 Kbps P2: 150000 Kbps P3: 150000 Kbps P4: 150000 Kbps P5: 150000 Kbps P6: 150000 Kbps P7: 150000 Kbps Sub-TLV: 9 Len: 4 ADMIN_GROUP : 00000002 (2) 01 (xlink) ------------------------------------------------------------------------------Opaque LSA ------------------------------------------------------------------------------Area Id : 0.0.0.0 Adv Router Id : 10.10.10.222 Link State Id : 1.0.0.4 LSA Type : Area Opaque Sequence No : 0x80000025 Checksum : 0xfcd9 Age : 262 Length : 124 Options : E Advertisement : LINK INFO TLV (0002) Len 100 : Sub-TLV: 1 Len: 1 LINK_TYPE : 2 Sub-TLV: 2 Len: 4 LINK_ID : 10.2.3.2 Sub-TLV: 3 Len: 4 LOC_IP_ADDR : 10.2.3.2 Sub-TLV: 4 Len: 4 REM_IP_ADDR : 0.0.0.0 Sub-TLV: 5 Len: 4 TE_METRIC : 100 Sub-TLV: 6 Len: 4 MAX_BDWTH : 1000000 Kbps Sub-TLV: 7 Len: 4 RSRVBL_BDWTH : 1000000 Kbps Sub-TLV: 8 Len: 32 UNRSRVD_CLS0 : P0: 150000 Kbps P1: 150000 Kbps P2: 150000 Kbps P3: 150000 Kbps P4: 150000 Kbps P5: 150000 Kbps P6: 150000 Kbps P7: 150000 Kbps Sub-TLV: 9 Len: 4 ADMIN_GROUP : 00000002 (2) 01 (xlink) -----output omitted------
13. On your P router change the bandwidth reservation of LSP #1 to 450Mbps. Use the ‘show router mpls lsp path detail’ command to view the LSP. Alcatel Multiprotocol Label Switching (MPLS) Lab Guide v1.1
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a. Is the LSP re-signaled with the new bandwidth? Why? 14. On your PE router change the bandwidth reservation of LSP #1 to 450Mbps. Use the ‘show router mpls lsp path detail’ command to view the LSP. a. Is the LSP re-signaled with the new bandwidth? Why? 15. On your P and PE routers use the ‘tools perform’ command to determine the path that would be taken by LSPs with these requirements. If a path is available what path is taken, if no path is available, why not? An example output is shown below. a. LSP 1 to diagonal P router excluding the admin-group xlink. b. LSP 2 to counter-clockwise P router including the admin-group xlink. c. LSP 3 to clockwise P router with bandwidth of 200Mbps. d. LSP 4 to diagonal P router with hop-limit of 3 and excluding the admin-group xlink e. LSP 5 to diagonal P router with hop-limit of 1 and excluding the admin-group xlink f. LSP 6 to clockwise P router excluding the admin-group xlink and excluding the interface from your P router to the clockwise P router. Note: To determine the bit-map value of the admin-group look at the LSA for the interface that is part of the admin-group, in the opaque database.
A:P3>tools>perform>router>mpls# cspf to 10.10.10.222 exclude-bitmap 2 CSPF Path To : 10.10.10.222 Path 1 : In: 10.10.10.223 Out: 10.3.4.3 -> In: 10.3.4.4 Out: 10.2.4.4 -> In: 10.2.4.2 Out: 10.10.10.222 A:P3>tools>perform>router>mpls# cspf to 10.10.10.224 include-bitmap 2 MINOR: CLI No CSPF path to "10.10.10.224" with specified constraints. A:P3>tools>perform>router>mpls# cspf to 10.10.10.221 bandwidth 200 CSPF Path To : 10.10.10.221 Path 1 : In: 10.10.10.223 Out: 10.1.3.3 -> In: 10.1.3.1 Out: 10.10.10.221 A:P3>tools>perform>router>mpls# cspf to 10.10.10.222 hop-limit 3 exclude-bitmap 2 CSPF Path To : 10.10.10.222 Path 1 : In: 10.10.10.223 Out: 10.3.4.3 -> In: 10.3.4.4 Out: 10.2.4.4 -> In: 10.2.4.2 Out: 10.10.10.222 A:P3>tools>perform>router>mpls# cspf to 10.10.10.222 hop-limit 1 exclude-bitmap 2 MINOR: CLI No CSPF path to "10.10.10.222" with specified constraints. A:P3>tools>perform>router>mpls# cspf to 10.10.10.221 exclude-bitmap 2 exclude-address 10.1.3.3 CSPF Path To : 10.10.10.221 Path 1 : In: 10.10.10.223 Out: 10.3.4.3 -> In: 10.3.4.4 Out: 10.2.4.4 -> In: 10.2.4.2 Out: 10.1.2.2 -> In: 10.1.2.1 Out: 10.10.10.221
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Lab 5 Review Questions
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1. 2. 3.
What constraints does the 7x50 take into consideration for LSP path computation? What happens if the CSPF configuration is omitted from a LSP configured with a particular bandwidth requirement or admin-group inclusion/exclusion? What is the difference in behavior when you change the bandwidth of a LSP configured with SE reservation style versus FF?
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Lab 6
Enabling Primary and Secondary LSP Tunnels
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Objective: The purpose of this lab is to configure an LSP using RSVP-TE and observe the protection mechanism provided by configuring both a Primary and Secondary path for the LSP.
Primary Path for LSP P3-P2
Secondary Path for LSP P3-P2
Service Provider Network LDP Enabled Core
Edge 1
Edge 2
10.32.1.0/24
10.16.1.0/24
Pod 1
Pod 2 Core 1
Core 2 10.x.y.z/24
Core 3
Core 4
Pod 3 10.48.1.0/24
Edge 4
Edge 3 Primary Path for LSP PE3-P2
Pod 4
10.64.1.0/24
Secondary Path for LSP PE3-P2
Figure 6-1: Enabling Primary and Secondary LSP Tunnels
Syntax: The configuration and verification commands required for this Lab are provided in Table 6-1. Refer to the student guide for additional command details. Each command may have additional parameters possible. Use the â&#x20AC;&#x2DC;?â&#x20AC;&#x2122; character for help and to explore all command line options. Other commands may also be used, including those found in previous exercises and courses.
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Lab 6 Command list #configure router mpls path <path-name> #configure router mpls path <path-name> hop <index> [strict | loose] #configure router mpls lsp <lsp-name> #configure router mpls lsp <lsp-name> to <system-id> #configure router mpls lsp <lsp-name> cspf #configure router mpls lsp <lsp-name> primary <path-name> #configure router mpls lsp <lsp-name> secondary <path-name> #configure router mpls lsp <lsp-name> secondary <path-name> standby #show router rsvp session #show router mpls path #show router mpls lsp [detail] #show router mpls lsp <lsp-name> path detail #show router mpls lsp transit detail #show router mpls lsp terminate detail
Table 6-1: Lab 6 Configuration and Verification Commands
Exercise: This lab consists of three phases. In phase one you configure a LSP with a Primary and Secondary path, and examine the results. In phase two you reconfigure the Secondary path to be in “standby” mode and again examine the results. In phase three you shut down an interface which affects the primary path and observe the results of the secondary path providing a backup to the primary path. Phase I 1. You will configure your P or PE router as the Tunnel head with the tail end being the P router connected to the diagonally connected Pod’s P router. For example, if you are in Pod 3 then your P3 or PE3 router will be your tunnel head. The tunnel end will be the P2 router in your diagonally connected Pod. Follow these steps: a. Configure a strict hop path from your P or PE router using the router clockwise from your Pod to get to the diagonally opposite P router. For example, if you are on P3 or PE3 then use P1 in the path to get to P2. Note that on the PE router there is an additional hop to reach the P router first. b. Configure an LSP from your P or PE router to the P router in the diagonally connected Pod using the strict path you configured in the previous step as the primary path and using the loose path configured in the previous lab as the secondary path. Do not configure the standby option for the secondary path. Do not allocate bandwidth, hop-limit or admin-group inclusion/exclusion, and do not enable CSPF for this LSP. 2. Perform the verification steps below, and then continue with phase two of the lab. Phase II 1. Configure the standby secondary path option in order to enable the standby path in a “hot standby” mode. 2. Repeat verification steps below and notice the change in the secondary path state. Continue with phase three of the lab. Phase III
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1.
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2. 3.
Ask the person who is using the router clockwise from you to shutdown their interface between their router and your tunnel end point. For example, if you are on P3 then P1 will shut down the interface between P1 and P2. You should now notice that the secondary link becomes the new “active link”. Use the command “show router mpls lsp <lsp name> detail command. Again, repeat the verification steps below to confirm that the secondary path has now become the active path. Once you have confirmed the path, ask your neighbor to now bring up the interface and ensure that the primary path is now the active path.
Verification: 1.
Use the “show router mpls path” command to confirm that the paths you have configured are administratively “up” and that the hops have been defined correctly. An example of the output is shown. a. What is the difference between “Strict” and “Loose” paths?
A:P3# show router mpls path =============================================================================== MPLS Path: =============================================================================== Path Name Adm Hop Index IP Address Strict/Loose ------------------------------------------------------------------------------P3-P1-P2 Up 1 10.1.3.1 Strict 2 10.1.2.2 Strict loose
Up
no hops
n/a
n/a
------------------------------------------------------------------------------Paths : 2 =============================================================================== A:P3#
2.
On your P and PE router, use the command “show router mpls lsp” to verify that your LSP operationally UP. Also note that the LSP is an Originating LSP. An example of the output is shown.
A:P3# show router mpls lsp =============================================================================== MPLS LSPs (Originating) =============================================================================== LSP Name To Fastfail Adm Opr Config ------------------------------------------------------------------------------LSP-P3-P2 10.10.10.222 No Up Up ------------------------------------------------------------------------------LSPs : 1 =============================================================================== A:P3#
3.
On your P router, verify if there are any transiting or terminating LSPs. An example of the output is shown. a. Where do the transiting LSPs come from? b. Where do the terminating LSPs come from?
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A:P1# show router mpls lsp transit =============================================================================== MPLS LSPs (Transit) =============================================================================== Legend : @ - Active Detour =============================================================================== From To In I/F Out I/F State LSP Name ------------------------------------------------------------------------------10.10.10.223 10.10.10.222 1/1/4 1/1/2 Up P3-P2::P3-P1-P2 10.10.10.243 10.10.10.222 1/1/4 1/1/2 Up PE3-P2::PE3-P3-P1-P2 ------------------------------------------------------------------------------LSPs : 2 ===============================================================================
A:P1# show router mpls lsp terminate =============================================================================== MPLS LSPs (Terminate) =============================================================================== Legend : @ - Active Detour =============================================================================== From To In I/F Out I/F State LSP Name ------------------------------------------------------------------------------10.10.10.224 10.10.10.221 1/1/4 n/a Up P4-P1::to-P1 10.10.10.244 10.10.10.221 1/1/4 n/a Up PE4-P1::to-P1 ------------------------------------------------------------------------------LSPs : 2 ===============================================================================
4.
Use the command â&#x20AC;&#x153;show router mpls lsp <lsp name> path detailâ&#x20AC;? to view the path being used. Also to show that the secondary LSP had not been signaled and is therefore down. An example of the output is shown. a. What is the operational state of the Primary path? b. What is the operational state of the Secondary path? Explain.
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A:P3# show router mpls lsp LSP-P3-P2 path detail =============================================================================== MPLS LSP LSP-P3-P2 Path (Detail) =============================================================================== Legend : @ - Detour Available # - Detour In Use b - Bandwidth Protected n - Node Protected =============================================================================== ------------------------------------------------------------------------------LSP LSP-P3-P2 Path P3-P1-P2 ------------------------------------------------------------------------------LSP Name : LSP-P3-P2 Path LSP ID : 1 From : 10.10.10.223 To : 10.10.10.222 Adm State : Up Oper State : Up Path Name : Primary_Path Path Type : Primary Path Admin : Up Path Oper : Up OutInterface: 1/1/3 Out Label : 131063 Path Up Time: 0d 00:12:51 Path Dn Time : 0d 00:00:00 Retry Limit : 0 Retry Timer : 30 sec RetryAttempt: 0 Next Retry In : 0 sec Bandwidth : No Reservation Oper Bandwidth : 0 Mbps Hop Limit : 255 Record Route: Record Record Label : Record Oper MTU : 9198 Negotiated MTU : 9198 Adaptive : Enabled MBB State : N/A Include Grps: Exclude Grps : None None Path Trans : 1 CSPF Queries : 1 Failure Code: noError Failure Node : n/a ExplicitHops: 10.1.3.1 -> 10.1.2.2 Actual Hops : 10.1.3.3(10.10.10.223) -> 10.1.3.1(10.10.10.221) Record Label : 131063 -> 10.1.2.2(10.10.10.222) Record Label : 131063 ComputedHops: 10.1.3.3 -> 10.1.3.1 -> 10.1.2.2 ------------------------------------------------------------------------------LSP LSP-P3-P2 Path loose ------------------------------------------------------------------------------LSP Name : LSP-P3-P2 Path LSP ID : 1 From : 10.10.10.223 To : 10.10.10.222 Adm State : Up Oper State : Up Path Name : loose Path Type : Secondary Path Admin : Up Path Oper : Up OutInterface: 1/2/3 Out Label : 131070 Path Up Time: 0d 00:00:06 Path Dn Time : 0d 00:00:00 Retry Limit : 0 Retry Timer : 30 sec RetryAttempt: 0 Next Retry In : 0 sec Bandwidth : No Reservation Oper Bandwidth : 0 Mbps Hop Limit : 255 Record Route: Record Record Label : Record Oper MTU : 9198 Negotiated MTU : 9198 Adaptive : Enabled MBB State : N/A Include Grps: Exclude Grps : None None Path Trans : 1 CSPF Queries : 0 Failure Code: noError Failure Node : n/a ExplicitHops: No Hops Specified Actual Hops : 10.2.3.3 -> 10.2.3.2 Record Label : 131070 ===============================================================================
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5.
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Connect to your neighbor’s P router (the one in the path of your Primary path). Use the “show router mpls lsp transit detail” command on your neighbor’s transit P router (in this example if you are in Pod 3 then you will be connecting to P1) to show that this router is in the path of the LSP. Also use this command to see the labels being assigned. An example output is shown. a. Which direction is the “In Interface” pointing? b. Which direction is the “Out Interface” pointing? c. Which router’s address is the “Previous Hop” address? d. Is there any difference in this output in Phase II? e. In Phase III, do you see your LSP transiting on your neighbor’s P router? Why?
A:P1# show router mpls lsp transit detail =============================================================================== MPLS LSPs (Transit) (Detail) =============================================================================== ------------------------------------------------------------------------------LSP LSP-P3-P2::P3-P1-P2 ------------------------------------------------------------------------------From : 10.10.10.223 To : 10.10.10.222 State : Up In Interface : 1/1/3 In Label : 131063 Out Interface : 1/1/2 Out Label : 131063 Previous Hop : 10.1.3.3 Next Hop : 10.1.2.2 Reserved BW : 0 Kbps ===============================================================================
6.
Use the command “show router mpls lsp terminate detail” on the destination router (in this case if you are in Pod 3, then the destination router is P2). An example output is shown. a. Is there any difference in this output in Phase II? b. Is there any difference in this output in Phase III?
A:P2# show router mpls lsp terminate detail =============================================================================== MPLS LSPs (Terminate) (Detail) =============================================================================== ------------------------------------------------------------------------------LSP LSP-P3-P2::P3-P1-P2 ------------------------------------------------------------------------------From : 10.10.10.223 To : 10.10.10.222 State : Up In Interface : 1/1/2 In Label : 131063 Previous Hop : 10.1.2.1 =============================================================================== A:P2#
7.
On your P or PE router verify the RSVP sessions that are established. An example output is shown. a. How many RSVP sessions are there, and what LSPs do they correspond to? b. What identifies the LSP and what identifies the path?
Lab 6 Review Questions 1. 2. 3.
Can you configure a Primary path with strict hops and a Secondary path with no hops specified? What can be a consequence of doing this? Do the Primary and Secondary paths of a LSP use the same label at the destination router? What is the difference between having a Secondary path that standby versus not standby?
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Lab 7
FRR One-to-One Protection
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Objective: The purpose of this lab is to configure an LSP using RSVP-TE and observe the protection mechanism provided by configuring Fast-Reroute in One-to-One mode for the LSP.
Service Provider Network LDP Enabled Core
Edge 1
10.16.1.0/24
Edge 2
10.32.1.0/24
Pod 1
Pod 2 Core 1
Core 2 10.x.y.z/24
Core 3
Core 4
Pod 3 10.48.1.0/24
Edge 4
Edge 3 LSP PE3-PE2
Pod 4
10.64.1.0/24
LSP P3-P2
Figure 7-1: Enabling FRR One-to-One Protection
Syntax: The configuration and verification commands required for this Lab are provided in Table 7-1. Refer to the student guide for additional command details. Each command may have additional parameters possible. Use the â&#x20AC;&#x2DC;?â&#x20AC;&#x2122; character for help and to explore all command line options. Other commands may also be used, including those found in previous exercises and courses.
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Lab 7 Command list #configure router mpls lsp <lsp-name> fast-reroute one-to-one #show router mpls status #show router mpls lsp path detail #show router mpls lsp transit #show router mpls lsp transit detail #show router rsvp session detail
Table 7-1: Lab 7 Configuration and Verification Commands
Exercise: Figure 7-1 shows the primary LSP from Pod 3’s perspective. However for this lab each pod will be creating a strict LSP from their PE router to the PE router diagonally opposite, via the P router to their left (clockwise direction) and a strict LSP from their P router to the P router diagonally opposite, again via the P router to their left. For example, if you are on Pod 3, then this LSP will be from PE3 to PE2 through P3, P1 and P2. 1.
On your PE (or P) router create a path to the PE (or P) router of your diagonally connected Pod by using the P router of the Pod clockwise from your own. For example if you are in Pod 3, then your PE3 (or P3) router will be the Head end of a path going through P3, P1, P2, and then terminating at PE2 (or for the LSP originating on P3, P3 will be the Head end of the path going through P1 and terminating on P2). Use strict path hops all the way through. Note that for the P router, you can re-use the strict path you configured in Lab 6.
2.
Create a LSP as per Figure 7-1 making use of the path you just created as the Primary path. Enable One-toOne FRR for the LSP. (i.e. on your PE router, configure a LSP to the PE router in the diagonally connected Pod, and on your P router, configure a LSP to the P router in the diagonally connected Pod). Do not allocate bandwidth, hop-limit or admin-group inclusion/exclusion. Remember that CSPF must be enabled on the LSP.
3.
Verify the configuration by using the verification section below.
4.
Once your have verified your configuration, ask the person working on the P router clockwise from you to shutdown the interface leading away from you towards the LSP termination point. For example if you are on Pod 3, then the person on Pod 1 should shutdown the interface between P1 and P2.
5.
Once the link has been shutdown, again use the verification steps below to confirm the detour path.
6.
Once you have confirmed the detour path, the administrator of your “downed” link may again bring up the interface.
Verification: 1.
Verify that your LSP is enabled and operational. An example output is shown. a. How many Dynamic LSPs do you see on your PE router? b. How many Dynamic LSPs do you see on your P router?
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A:PE3# show router mpls status
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=============================================================================== MPLS Status =============================================================================== Admin Status : Up Oper Status : Up FR Object : Enabled Resignal Timer : Disabled LSP Counts Originate Transit Terminate ------------------------------------------------------------------------------Static LSPs 0 0 0 Dynamic LSPs 1 0 0 Detour LSPs 0 0 0 =============================================================================== A:PE3#
2.
Verify that your LSP is making use of the correct path and that the hops are accurately represented. An example output is shown. a. How many routers are showing Detour Available? b. Which router is showing a Detour Available? c. How many routers are showing â&#x20AC;&#x153;Node Protectâ&#x20AC;??
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A:PE3# show router mpls lsp path detail
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=============================================================================== MPLS LSP Path (Detail) =============================================================================== Legend : @ - Detour Available # - Detour In Use b - Bandwidth Protected n - Node Protected =============================================================================== ------------------------------------------------------------------------------LSP LSP-to-PE2 Path to-PE2 ------------------------------------------------------------------------------LSP Name : LSP-to-PE2 Path LSP ID : 1 From : 10.10.10.80 To : 10.10.10.78 Adm State : Up Oper State : Up Path Name : to-PE2 Path Type : Primary Path Admin : Up Path Oper : Up OutInterface: 1/1/1 Out Label : 131063 Path Up Time: 0d 00:01:40 Path Dn Time : 0d 00:00:00 Retry Limit : 0 Retry Timer : 30 sec RetryAttempt: 0 Next Retry In : 0 sec Bandwidth : No Reservation Oper Bandwidth : 0 Mbps Hop Limit : 255 Record Route: Record Record Label : Record Oper MTU : 1500 Negotiated MTU : 1500 Adaptive : Enabled MBB State : N/A Include Grps: Exclude Grps : None None Path Trans : 1 CSPF Queries : 1 Failure Code: noError Failure Node : n/a ExplicitHops: 10.48.1.1 -> 10.1.3.1 -> 10.1.2.2 -> 10.32.1.2 Actual Hops : 10.48.1.2(10.10.10.80) -> 10.48.1.1(10.10.10.79) @ n Record Label : 131063 -> 10.1.3.1(10.10.10.75) @ Record Label : 131062 -> 10.1.2.2(10.10.10.77) Record Label : 131062 -> 10.32.1.2(10.10.10.78) Record Label : 131070 ComputedHops: 10.48.1.2 -> 10.48.1.1 -> 10.1.3.1 -> 10.1.2.2 -> 10.32.1.2 =============================================================================== A:PE3#
3.
On your P router, view the LSPs that are transiting it. An example is shown.
A:P3# show router mpls lsp transit =============================================================================== MPLS LSPs (Transit) =============================================================================== Legend : @ - Active Detour =============================================================================== From To In I/F Out I/F State LSP Name ------------------------------------------------------------------------------10.10.10.80 10.10.10.78 1/1/1 1/1/3 Up LSP-to-PE2::to-PE2 ------------------------------------------------------------------------------LSPs : 1 =============================================================================== A:P3#
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4.
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On your P router use the above command “show router mpls lsp transit” but add the keyword detail to the end of the command. This command provides more information regarding the transiting LSPs through this router and can be used to troubleshoot the LSP. a. Which inbound interface is being used by the LSP you’ve configured? Which for Outbound? b. Which inbound interface is being used by the detour for the LSP you’ve configured? Which for Outbound? c. Is this node part of a “Node” or “Hop” detour for the LSP you’ve configured? How do you know? d. For which LSPs are the other detours shown generated? e. What changes in this output when the interface is shutdown and your LSP makes use of the detour?
A:P3# show router mpls lsp transit detail =============================================================================== MPLS LSPs (Transit) (Detail) =============================================================================== ------------------------------------------------------------------------------LSP LSP-to-PE2::to-PE2 ------------------------------------------------------------------------------From : 10.10.10.243 To : 10.10.10.242 State : Up In Interface : 1/1/1 In Label : 131063 Out Interface : 1/1/4 Out Label : 131062 Previous Hop : 10.48.1.2 Next Hop : 10.1.3.1 Reserved BW : 0 Kbps Detour Status : Standby Detour Type : Originate Detour Avoid Node/Hop: 10.10.10.221 Detour Origin : 10.10.10.223 Detour Active Time : n/a Detour Up Time: 0d 00:03:28 In Interface : 1/1/1 In Label : 131063 Out Interface : 1/1/3 Out Label : 131063 Next Hop : 10.2.3.2 Explicit Hops : 10.2.3.1 -> 10.2.3.1 -> 10.32.1.2 =============================================================================== A:P3#
5.
On your P router Use the command “show router rsvp session detail” to view all the RSVP sessions established on the router for every LSP and detour LSP originating, transiting or terminating on it. This command gives similar information as the “show router mpls lsp [transit | terminate]” command. a. Identify what LSPs are shown, to which LSP each detour shown belongs, and where these detours go. b. Trace out the end-to-end path taken by your LSP, when the interface is shutdown and the detour is used.
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A:P3# show router rsvp session detail
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=============================================================================== RSVP Sessions (Detailed) =============================================================================== ------------------------------------------------------------------------------LSP : LSP-P3-P2::Primary_Path ------------------------------------------------------------------------------From : 10.10.10.223 To : 10.10.10.222 Tunnel ID : 1 LSP ID : 1 Style : SE State : Up Session Type : Originate In Interface : n/a Out Interface : 1/1/4 In Label : n/a Out Label : 131063 Previous Hop : n/a Next Hop : 10.1.3.1 Hops : 10.1.3.1 -> 10.1.2.2 Path Recd : 0 Path Sent : 61 Resv Recd : 60 Resv Sent : 0 ------------------------------------------------------------------------------LSP : LSP-to-PE2::to-PE2 ------------------------------------------------------------------------------From : 10.10.10.243 To : 10.10.10.242 Tunnel ID : 1 LSP ID : 1 Style : SE State : Up Session Type : Transit In Interface : 1/1/1 Out Interface : 1/1/4 In Label : 131063 Out Label : 131062 Previous Hop : 10.48.1.2 Next Hop : 10.1.3.1 Path Recd : 14 Path Sent : 14 Resv Recd : 13 Resv Sent : 14 ------------------------------------------------------------------------------LSP : LSP-to-PE2::to-PE2_detour ------------------------------------------------------------------------------From : 10.10.10.243 To : 10.10.10.242 Tunnel ID : 1 LSP ID : 1 Style : SE State : Up Session Type : Originate (Detour) In Interface : 1/1/1 Out Interface : 1/1/3 In Label : 131063 Out Label : 131063 Previous Hop : 10.48.1.2 Next Hop : 10.3.4.4 Path Recd : 0 Path Sent : 13 Resv Recd : 13 Resv Sent : 0 =============================================================================== A:P3#
Lab 7 Review Questions 1. 2. 3.
Does the label stack grow when a detour LSP is used? What happens when node protection is requested but a given router cannot find a path which avoids the next-hop node? How does each router compute its detour for a given LSP?
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Lab 8
FRR Facility Backup Protection
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Objective: The purpose of this lab is to configure an LSP using RSVP-TE and observe the protection mechanism provided by configuring Fast-Reroute in Facilities Backup mode for the LSP.
Service Provider Network LDP Enabled Core
Edge 1
10.16.1.0/24
Edge 2
10.32.1.0/24
Pod 1
Pod 2 Core 1
Core 2 10.x.y.z/24
Core 3
Core 4
Pod 3 10.48.1.0/24
Edge 4
Edge 3 LSP PE3-PE2
Pod 4
10.64.1.0/24
LSP P3-P2
Figure 8-1: Enabling FRR Facility Bypass
Syntax: The configuration and verification commands required for this Lab are provided in Table 8-1. Refer to the student guide for additional command details. Each command may have additional parameters possible. Use the â&#x20AC;&#x2DC;?â&#x20AC;&#x2122; character for help and to explore all command line options. Other commands may also be used, including those found in previous exercises and courses.
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Lab 8 Command list #configure router mpls lsp <lsp-name> fast-reroute facility #show router mpls status #show router mpls lsp path detail #show router mpls bypass-tunnel detail #show router mpls bypass-tunnel protected-lsp detail #show router rsvp session bypass-tunnel #show router rsvp session bypass-tunnel detail #oam lsp-ping <lsp-name> #oam lsp-trace <lsp-name>
Table 8-1: Lab 8 Configuration and Verification Commands
Exercise: This lab re-uses the two LSPs created in the previous lab (one LSP from your PE router to the PE router of the diagonally connected Pod, and one LSP from your P router to the P router of the diagonally connected Pod. 1. 2.
Change the fast reroute configuration of both LSPs to Facility Backup. Verify that the LSPs are enabled. An example is shown below.
A:P3# show router mpls status =============================================================================== MPLS Status =============================================================================== Admin Status : Up Oper Status : Up FR Object : Enabled Resignal Timer : Disabled LSP Counts Originate Transit Terminate ------------------------------------------------------------------------------Static LSPs 0 0 0 Dynamic LSPs 1 1 0 Detour LSPs 0 0 0 ===============================================================================
3.
From your PE router, verify that your LSP is making use of the correct path and that the hops are accurately represented. a. Which routers are being used as Node backup? b. Which router is being used as a Link backup?
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A:PE3# show router mpls lsp path detail
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=============================================================================== MPLS LSP Path (Detail) =============================================================================== Legend : @ - Detour Available # - Detour In Use b - Bandwidth Protected n - Node Protected =============================================================================== ------------------------------------------------------------------------------LSP LSP-to-PE2 Path to-PE2 ------------------------------------------------------------------------------LSP Name : LSP-to-PE2 Path LSP ID : 3 From : 10.10.10.80 To : 10.10.10.78 Adm State : Up Oper State : Up Path Name : to-PE2 Path Type : Primary Path Admin : Up Path Oper : Up OutInterface: 1/1/1 Out Label : 131061 Path Up Time: 0d 00:01:13 Path Dn Time : 0d 00:00:00 Retry Limit : 0 Retry Timer : 30 sec RetryAttempt: 0 Next Retry In : 0 sec Bandwidth : No Reservation Oper Bandwidth : 0 Mbps Hop Limit : 255 Record Route: Record Record Label : Record Oper MTU : 1500 Negotiated MTU : 1500 Adaptive : Enabled MBB State : N/A Include Grps: Exclude Grps : None None Path Trans : 3 CSPF Queries : 2 Failure Code: noError Failure Node : n/a ExplicitHops: 10.48.1.1 -> 10.1.3.1 -> 10.1.2.2 -> 10.32.1.2 Actual Hops : 10.48.1.2(10.10.10.80) -> 10.48.1.1(10.10.10.79) @ n Record Label : 131061 -> 10.1.3.1(10.10.10.75) @ Record Label : 131060 -> 10.1.2.2(10.10.10.77) Record Label : 131057 -> 10.32.1.2(10.10.10.78) Record Label : 131069 ComputedHops: 10.48.1.2 -> 10.48.1.1 -> 10.1.3.1 -> 10.1.2.2 -> 10.32.1.2
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------------------------------------------------------------------------------LSP LSP-to-P2 Path to-P2 ------------------------------------------------------------------------------LSP Name : LSP-to-P2 Path LSP ID : 2 From : 10.10.10.80 To : 10.10.10.77 Adm State : Up Oper State : Up Path Name : to-P2 Path Type : Primary Path Admin : Up Path Oper : Up OutInterface: 1/1/1 Out Label : 131062 Path Up Time: 0d 00:09:02 Path Dn Time : 0d 00:00:00 Retry Limit : 0 Retry Timer : 30 sec RetryAttempt: 0 Next Retry In : 0 sec Bandwidth : No Reservation Oper Bandwidth : 0 Mbps Hop Limit : 255 Record Route: Record Record Label : Record Oper MTU : 1500 Negotiated MTU : 1500 Adaptive : Enabled MBB State : N/A Include Grps: Exclude Grps : None None Path Trans : 1 CSPF Queries : 1 Failure Code: noError Failure Node : n/a ExplicitHops: 10.48.1.1 -> 10.1.3.1 -> 10.1.2.2 Actual Hops : 10.48.1.2(10.10.10.80) -> 10.48.1.1(10.10.10.79) @ n Record Label : 131062 -> 10.1.3.1(10.10.10.75) @ Record Label : 131061 -> 10.1.2.2(10.10.10.77) Record Label : 131060 ComputedHops: 10.48.1.2 -> 10.48.1.1 -> 10.1.3.1 -> 10.1.2.2 ==============================================================================
4.
On your P router, confirm that both Protected LSPs are being backed up by the one bypass tunnel. An example is shown below. a. Which LSPs do the bypass tunnels seen protect? b. What path does each bypass tunnel take?
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A:P3# show router mpls bypass-tunnel detail
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=============================================================================== MPLS Bypass Tunnels (Detail) =============================================================================== ------------------------------------------------------------------------------Bypass-Tunnel-Avoid-Node10.10.10.221 ------------------------------------------------------------------------------To : 10.2.3.2 State : Up Out I/F : 1/1/3 Out Label : 131060 Up Time : 0d 00:09:13 Active Time : n/a Reserved BW : 0 Kbps Protected LSP Count : 2 Actual Hops : 10.2.3.3 -> 10.2.3.2 -> 10.2.4.2 ------------------------------------------------------------------------------bypass-link10.1.3.2 ------------------------------------------------------------------------------To : 10.1.4.1 State : Up Out I/F : 1/1/2 Out Label : 131071 Up Time : 0d 01:24:45 Active Time : n/a Reserved BW : 0 Kbps Protected LSP Count : 2 Actual Hops : 10.3.4.3 -> 10.3.4.4 -> 10.1.4.1 ===============================================================================
5.
On the P router view the LSPs that are protected by the bypass. An example is shown below. a. What is the Downstream Label?
A:P3# show router mpls bypass-tunnel protected-lsp detail =============================================================================== MPLS Bypass Tunnels (Detail) =============================================================================== ------------------------------------------------------------------------------Bypass-Tunnel-Avoid-Node10.10.10.75 ------------------------------------------------------------------------------To : 10.2.4.2 State : Up Out I/F : 1/1/2 Out Label : 131060 Up Time : 0d 00:09:57 Active Time : n/a Reserved BW : 0 Kbps Protected LSP Count : 2 Actual Hops : 10.3.4.3 -> 10.3.4.4 -> 10.2.4.2 Protected LSPs LSP Name : From : Avoid Node/Hop : Bandwidth :
LSP-to-P2::to-P2 10.10.10.80 10.1.3.1 0 Kbps
To Downstream Label
: 10.10.10.77 : 131060
LSP Name From Avoid Node/Hop Bandwidth
LSP-to-PE2::to-PE2 10.10.10.80 To 10.1.3.1 Downstream Label 0 Kbps
: 10.10.10.78 : 131057
: : : :
===============================================================================
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6.
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On your P router view the RSVP session for the bypass tunnel. An example is shown below below. a. Which router is the PLR? b. Which router is the MP?
A:P3# show router rsvp session bypass-tunnel =============================================================================== RSVP Sessions =============================================================================== From To Tunnel LSP Name State ID ID ------------------------------------------------------------------------------10.10.10.79 10.2.4.2 2 3 Bypass-Tunnel-Avoid-Node10.* Up ------------------------------------------------------------------------------Sessions : 1 =============================================================================== * indicates that the corresponding row element may have been truncated. A:P3#
7.
On your P router use the command “show router rsvp session bypass-tunnel detail” to discover more specific information about your bypass tunnel. An example is shown below below. a. What is the Style type of the Bypass tunnel? b. Why is there only 1 Out Label being displayed?
A:P3# show router rsvp session bypass-tunnel detail =============================================================================== RSVP Sessions (Detailed) =============================================================================== ------------------------------------------------------------------------------LSP : Bypass-Tunnel-Avoid-Node10.10.10.75 ------------------------------------------------------------------------------From : 10.10.10.79 To : 10.2.4.2 Tunnel ID : 2 LSP ID : 3 Style : FF State : Up Session Type : Bypass Tunnel In Interface : n/a Out Interface : 1/1/2 In Label : n/a Out Label : 131060 Previous Hop : n/a Next Hop : 10.3.4.4 Path Recd : 0 Path Sent : 27 Resv Recd : 27 Resv Sent : 0 =============================================================================== A:P3#
8.
On your P router use the command “show router mpls bypass-tunnel protected-lsp <lsp-name::path-name> detail” to determine what bypass tunnel is protecting the LSP you configured from your P router to the diagonally connected P router. An example output is shown below. This command is useful when there are many bypass tunnels on a router.
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A:P3# show router mpls bypass-tunnel protected-lsp toP2::P3-P1-P2 detail =============================================================================== MPLS Bypass Tunnels (Detail) =============================================================================== ------------------------------------------------------------------------------bypass-node10.10.10.221 ------------------------------------------------------------------------------To : 10.2.3.2 State : Up Out I/F : 1/2/3 Out Label : 131054 Up Time : 0d 00:19:36 Active Time : n/a Reserved BW : 0 Kbps Protected LSP Count : 2 Actual Hops : 10.2.3.3 -> 10.2.3.2 Protected LSPs LSP Name : From : Avoid Node/Hop : Bandwidth :
lab8::P3-P1-P2 10.10.10.243 10.1.3.1 0 Kbps
To Downstream Label
: 10.10.10.242 : 131055
LSP Name From Avoid Node/Hop Bandwidth
lab8::P3-P1-P2 10.10.10.223 10.1.3.1 0 Kbps
To Downstream Label
: 10.10.10.222 : 131052
9.
: : : :
On your P router view the transiting LSPs. An example is shown below. a. Which LSPs transit your P router?
A:P3# show router mpls lsp transit =============================================================================== MPLS LSPs (Transit) =============================================================================== Legend : @ - Active Detour =============================================================================== From To In I/F Out I/F State LSP Name ------------------------------------------------------------------------------10.10.10.244 10.10.10.241 1/1/2 1/1/4 Up to-PE1::P4-P3-P1 10.10.10.243 10.10.10.242 1/1/1 1/1/4 Up to-PE2::P3-P1-P2 10.10.10.221 10.2.3.2 1/1/4 1/1/3 Up bypass-link10.1.2.2 ------------------------------------------------------------------------------LSPs : 3 ===============================================================================
10. Ask the person working on the P router clockwise from you to shutdown the interface leading away from you towards the LSP termination point. For example if you are on Pod 3, then the person on Pod 1 should shutdown the interface between P1 and P2. 11. Verify that the LSPs you configured on your PE and P routers are using the bypass tunnel by using the ‘show router mpls lsp path detail’ command, and by performing a lsp-trace. An example is shown below.
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A:PE3# show router mpls lsp path detail
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=============================================================================== MPLS LSP Path (Detail) =============================================================================== Legend : @ - Detour Available # - Detour In Use b - Bandwidth Protected n - Node Protected =============================================================================== ------------------------------------------------------------------------------LSP to-PE2 Path P3-P1-P2 ------------------------------------------------------------------------------LSP Name : to-PE2 Path LSP ID : 3 From : 10.10.10.243 To : 10.10.10.242 Adm State : Up Oper State : Up Path Name : P3-P1-P2 Path Type : Primary Path Admin : Up Path Oper : Up OutInterface: 1/2/1 Out Label : 131069 Path Up Time: 0d 01:00:12 Path Dn Time : 0d 00:00:00 Retry Limit : 0 Retry Timer : 30 sec RetryAttempt: 0 Next Retry In : 0 sec Bandwidth : No Reservation Oper Bandwidth : 0 Mbps Hop Limit : 255 Record Route: Record Record Label : Record Oper MTU : 9198 Negotiated MTU : 9198 Adaptive : Enabled MBB State : Success Include Grps: Exclude Grps : None None Path Trans : 2 CSPF Queries : 0 Failure Code: noError Failure Node : n/a ExplicitHops: 10.10.10.223 -> 10.10.10.221 -> 10.10.10.222 Actual Hops : 10.48.1.2 -> 10.48.1.1 @ n Record Label : 131069 -> 10.1.3.1 @ # Record Label : 131070 -> 10.2.3.2 Record Label : 131069 -> 10.32.1.2 Record Label : 131069 -------------------------------------------------------------------------------
Lab 8 Review Questions 1. 2. 3.
Does the label stack grow when a bypass tunnel is used? How does each router compute its detour for a given LSP? If an LSP is created from your PE router to the PE router in the Pod that is clockwise from yours, will it be protected by the bypass tunnel created by your P router for the two LSPs created in this Lab?
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Lab Solutions and Answers
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Lab 1 Solution – Lab Infrastructure and IGP Configuration The configuration is for P1. #-------------------------------------------------echo "OSPF Configuration" #-------------------------------------------------ospf area 0.0.0.0 interface "system" exit interface "P1-P2" exit interface "P1-P3" exit interface "P1-P4" exit interface "P1-PE1" exit exit exit
Lab 1 - Review Question Answers 1.
What is the routed path between PE1 and PE2 routers under normal circumstances? The routed path between PE1 and PE2 routers will normally flow via the PE1 – P1 – P2 – PE2 path. There is core redundancy so Multi-path is available, and if a link is shutdown or routing metrics change then the routed path may change.
Lab 2 Solution – Configuring a Static LSP The configuration below is for PE1. #-----------------------------------------# "MPLS Configuration" #-----------------------------------------configure router mpls # LSP from ingress of PE1 using P1 and P2 as transit LSRs to egress of PE2 static-lsp "PE1 to PE2" to 10.10.10.242 push 999 nexthop 10.16.1.1 no shutdown exit # LSP from ingress of PE2 using P1 and P2 as transit LSRs to egress of PE1 interface "PE1-P1" label-map 597 pop no shutdown
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exit exit all
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admin save The configuration below is for P1. #-----------------------------------------# "MPLS Configuration" #-----------------------------------------configure router mpls # LSP from ingress of PE1 using P1 and P2 as transit LSRs to egress of PE2 interface "P1-PE1" label-map 999 swap 998 nexthop 10.1.2.2 no shutdown exit exit # LSP from ingress of PE2 using P1 and P2 as transit LSRs to egress of PE1 interface "P1-P2" label-map 598 swap 597 nexthop 10.16.1.2 no shutdown exit exit all
Lab 2 - Review Question Answers 1.
How many static LSPs are required between 2 routers to create an end to end path? Two static LSPs are required between 2 routers to create an end to end path, one for each direction.
2.
Which range of label values is reserved for static LSP configurations? The label range of 32 through 1023 is reserved for static LSP configurations.
Lab 3 Solution – LDP Implementation Lab 3 Section 3.1 Solution – LDP Session Establishment Output of the LDP event debug on the P router: :P3>config>router>ldp# 97 2006/09/20 00:02:20.36 UTC MINOR: DEBUG #2001 - LDP "LDP: Session Created LDP entity for peer LDP LSR ID 10.10.10.243:0" 98 2006/09/20 00:02:20.36 UTC MINOR: DEBUG #2001 - LDP "LDP: Session Creating hello adjacency for peer 10.10.10.243:0." 99 2006/09/20 00:02:20.36 UTC MINOR: DEBUG #2001 - LDP "LDP: Session Created Hello Adjacency for peer LDP LSR ID 10.10.10.243:0" 100 2006/09/20 00:02:20.36 UTC MINOR: DEBUG #2001 - LDP "LDP: Session
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Taking passive role in LDP session setup."
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101 2006/09/20 00:02:20.36 UTC MINOR: DEBUG #2001 - LDP "LDP: Session Established connection to peer 10.10.10.243:0" 102 2006/09/20 00:02:20.36 UTC MINOR: DEBUG #2001 - LDP "LDP: Session Changing state from Inactive to InitializingHello for peer 10.10.10.243:0." 103 2006/09/20 00:02:20.36 UTC MINOR: DEBUG #2001 - LDP "LDP: Session TCP connection set up to 10.10.10.243." 104 2006/09/20 00:02:20.36 UTC MINOR: DEBUG #2001 - LDP "LDP: Session Established connection to peer 10.10.10.243:0" 105 2006/09/20 00:02:20.36 UTC MINOR: DEBUG #2001 - LDP "LDP: Session Changing state from InitializingHello to InitializedPassive for peer 10.10.10.24 3:0." 106 2006/09/20 00:02:20.36 UTC MINOR: DEBUG #2001 - LDP "LDP: Session Creating peer to 10.10.10.243:0." 107 2006/09/20 00:02:20.36 UTC MINOR: DEBUG #2001 - LDP "LDP: Session LDP Peer set up to 10.10.10.243:0." 108 2006/09/20 00:02:20.36 UTC MINOR: DEBUG #2001 - LDP "LDP: Session Sending Init to 10.10.10.243:0." 109 2006/09/20 00:02:20.36 UTC MINOR: DEBUG #2001 - LDP "LDP: Session Sending Keepalive to 10.10.10.243:0." 110 2006/09/20 00:02:20.36 UTC MINOR: DEBUG #2001 - LDP "LDP: Session Changing state from InitializedPassive to OpenRec for peer 10.10.10.243:0." 111 2006/09/20 00:02:20.36 UTC MINOR: DEBUG #2001 - LDP "LDP: Session Changing keepalive timeout to 30 for peer 10.10.10.243:0." 112 2006/09/20 00:02:20.36 UTC MINOR: DEBUG #2001 - LDP "LDP: Session Resetting keepalive timeout timer peer = 10.10.10.243:0" 113 2006/09/20 00:02:20.38 UTC MINOR: DEBUG #2001 - LDP "LDP: Session Changing state from OpenRec to Operational for peer 10.10.10.243:0." 114 2006/09/20 00:02:20.38 UTC MINOR: DEBUG #2001 - LDP "LDP: Session Creating session for peer 10.10.10.243:0." 115 2006/09/20 00:02:20.38 UTC MINOR: DEBUG #2001 - LDP "LDP: Session LDP Session set up to 10.10.10.243:0."
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116 2006/09/20 00:02:20.38 UTC MINOR: DEBUG #2001 - LDP "LDP: Session Sending Address to 10.10.10.243:0." 117 2006/09/20 00:02:20.38 UTC MINOR: DEBUG #2001 - LDP "LDP: Session Setting keepalive timer for peer 10.10.10.243:0." 118 2006/09/20 00:02:20.38 UTC MINOR: DEBUG #2001 - LDP "LDP: Session Resetting keepalive timeout timer peer = 10.10.10.243:0" 119 2006/09/20 00:02:20.38 UTC MINOR: DEBUG #2001 - LDP "LDP: Binding Sending Label mapping msg for Prefix: 10.10.10.223/32 to peer 10.10.10.243:0." 120 2006/09/20 00:02:20.38 UTC MINOR: DEBUG #2001 - LDP "LDP: Session Resetting keepalive timer peer = 10.10.10.243:0"
Lab 3 Section 3.1 - Answers to Exercise Questions 3a. After the hello adjacency is established what must happen before the LDP session can be established? The TCP connection must be established. 3b. What state occurs after the Active router sends the Initialization message to the Passive router? The Active router enters the OpenSent state. The Passive router responds with an Initialization message and enters the OpenRec state. 3c. When can label advertisement start occurring? When both routers have entered the Operational state. 6a. What LDP message is sent to the PE router? A notification message is sent to indicate that the LDP session is torn down. 7a. Which router plays the active role? The router with the higher system address, which in this case is the PE router.
Lab 3 Section 3.2 â&#x20AC;&#x201C; Configuring and Verifying the Provider Core for LDP The configuration below is for PE1. #-----------------------------------------# "LDP Configuration" #-----------------------------------------configure router ldp interface-parameters interface "PE1-P1" exit exit targeted-session disable-targeted-session Alcatel Multiprotocol Label Switching (MPLS) Lab Guide v1.1
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exit all
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Lab 3 Section 3.2 - Answers to Exercise Questions 2a. How many LDP neighbors should each P router have? 4 2b. How many LDP neighbors should each PE router have? 1 3a. How many LDP sessions does your P router have? 4 3b. How many LDP sessions does your PE router have? 1 3c What types of adjacencies are formed? Why? Link adjacencies are formed because the LDP peers are directly connected to each other. 4a. How many prefix bindings should be present? Explain There should be 32 prefix bindings – there are 8 prefixes (FECs) and the P router receives labels for these FECs from 4 peers. 4b. Should the P and PE routers have the same number of prefix bindings? No. PE router should have 8 prefix bindings – it receives a label for each binding only from one peer, the P router. 4c. What is the label generated by your P router for the FEC corresponding to its system address? Depends on output. 4d. On your P router, what is the label received from the diagonally connected P router for the FEC corresponding to the diagonally connected pod’s PE router? Depends on output. 4e. Why does your P router have some labels that are not in use? The labels not in use indicate that the router has generated a label for a given FEC, and that the next hop to reach that FEC is the peer router. Therefore, the P router will not advertise a label to one of its peers, if that peer is the next hop to reach the FEC for which the label is generated. 5a. What is the difference in the ‘show router ldp bindings’ when the ‘active’ keyword is used? Why are there fewer prefix bindings in the LFIB than the LIB? The former command gives the LIB and the latter gives the LFIB. The LIB contains all labels received for a given FEC, while the LFIB only contains the label that is actually used to forward packets. This active label corresponds to the label received from the router that is the next-hop to reach that FEC. 5b. Why does your P router have both a PUSH and SWAP operation for the prefix corresponding to your PE router? The PUSH operation applies when unlabelled packets destined for the FEC arrive at the router, while the SWAP operation applies when labeled packets with the corresponding ingress label arrive at the router. 5c. Based on the output of the ‘show router ldp bindings active’ command can you tell the system address of the router on which the command is executed? Yes, by looking at the prefix for which the operation is POP. 5d. Identify all the label mappings corresponding to the LSP extending from your PE router to the PE router of the diagonally connected Pod. At each router along the path identify the label that is PUSHed, SWAPed or POPed. Depends on output 6a. What are the FECs for which the LSPs have been created?
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Every router’s system address.
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6b. What does the metric value represent? This corresponds to the path cost to reach the FEC based on the OSPF metrics of each link. 8a. How has the LIB changed on the P and PE router compared to before the interface shutdown? The LIB on the P router has 8 fewer prefix bindings because the router no longer receives bindings from its diagonally connected neighbor. The LIB on the PE router does not change. 9a. How has the LFIB changed on the P and PE router compared to before the interface shutdown? On the P router the active label binding used to reach the diagonally connected neighbor Pod’s P and PE routers have changed. The LFIB on the PE router has not changed. 9b. What is the LSP path for packets originating on your PE router and destined for your diagonally connected neighbor Pod’s PE router now? Depends on output 9c. What label does your P router SWAP in for a packet coming in from your PE router destined for your diagonally connected neighbor Pod’s PE router? Depends on output
Lab Section 3.3 Solution – Enabling ECMP LDP The configuration below is for PE1 #-------------------------------------------------echo "Router (Network Side) Configuration" #-------------------------------------------------router interface "PE1-P1" address 10.16.1.2/24 port 1/2/1 exit interface "system" address 10.10.10.241/32 exit ecmp 4
Lab 3 Section 3.3 - Answers to Exercise Questions 3a. Is there any difference on your P and PE with the output of the LIB without ECMP LDP enabled? The LIB of the PE router does not change. On the P router it can be seen in the LIB that the router does not use the labels it has generated for the FEC corresponding to the diagonally connected Pod’s P and PE routers and advertised to the peer routers which are the next-hops to reach that Pod. 3b. How many Prefixes bindings should be present in your P and PE router’s LIB? Explain. The LIB of the P and PE routers have the same number of prefix bindings as before because the LIB contains labels received from all peers for a given FEC. 4a. Is there any difference on your P and PE routers with the output of the LFIB without ECMP LDP enabled? The LFIB of the PE router has no difference. The LFIB of the P router now has two additional entries for the FECs corresponding to the diagonally connected Pod’s P and PE routers.
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4b. How many equal cost LSPs are there from your P router to the PE router in the diagonally connected neighbor Pod? Two.
Lab 3 Section 3.4 Solution â&#x20AC;&#x201C; Applying Export Policy for Label Distribution The configurations below are for P1. #-------------------------------------------------echo "LDP Configuration" #-------------------------------------------------ldp export "export" interface-parameters interface "P1-P2" exit interface "P1-P3" exit interface "P1-P4" exit interface "P1-PE1" exit exit targeted-session disable-targeted-session exit exit exit #-------------------------------------------------echo "Policy Configuration" #-------------------------------------------------policy-options begin policy-statement "export" entry 10 action accept exit exit exit commit exit exit
Lab 3 Section 3.4 - Answers to Exercise Questions 3a. For what additional FEC are labels now generated? With the export policy labels are now generated for all direct connected interfaces on the router. 3b. How many prefixes bindings should be present? Explain. There should be 8 additional prefix bindings â&#x20AC;&#x201C; one for each link between the routers, except for the links whose interfaces have been shutdown (i.e. interfaces between P1 & P4 and between P2 & P3).
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Lab 3 Section 3.5 Solution – Configuring Targeted LDP The configuration below is for PE1. #-----------------------------------------# "LDP Configuration" #-----------------------------------------configure router ldp targeted-session no disable-targeted-session peer 10.10.10.60 exit peer 10.10.10.83 exit peer 10.10.10.156 exit all
Lab 3 Section 3.5 - Answers to Exercise Questions 3a. What adjacency types are established between the PE routers? Why? The adjacency established between the PE routers is “Targeted” because they are not directly connected to each other. 3b. What adjacency type is established between your PE and P routers? Why? The adjacency established between your PE and P router is “Both” because there is both a Link adjacency and a Targeted adjacency. The Link adjacency is established by having configured LDP on the interface between the two routers. The Targeted adjacency is established by having configured a targeted peer session between the two routers. 4a. How many direct and targeted LDP peers do your PE and P routers have? The PE router has one direct and four targeted peers. The P router has four direct and one targeted peers. 4b. How many LDP sessions do your PE & P routers have? The PE and P routers both have 4 LDP sessions. 4c. What are the FECs sent by your PE and P routers? The P & PE routers advertise a label for each FEC (i.e. system address of every known router) to each of its LDP peers. However it does not advertise a label for the FEC that corresponds to the LDP peer’s system address. (i.e. it does not advertise a label to a peer, when the FEC for which the label is generated is local to that peer). 4d. What are the FECs received by your PE and P routers? The P & PE routers receive a label for each FEC (i.e. system address of every known router) except its own system address, from each of its LDP peers.
Lab 3 - Review Question Answers 1.
Which command may be used to view the details of each LDP peer? The ‘show router ldp session detail’ command may be used to view the details of each LDP peer.
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2.
Is it possible for two routers to form both a link and a targeted LDP adjacency? Two routers may form both a link and targeted LDP adjacency if they share a common data link and a targeted session s configured between them.
3.
For which FECs are labels advertised by default? How can additional FECs be advertised? By default a 7x50 SR/ESS only advertises labels for its own system interface. An export policy is needed to avertise labels for other FECs in the 7x50 SR/ESS’s routing table.
4.
How does a router determine which LSP to use when ECMP LDP is enabled? The LSP used to forward traffic is based on a hashing algorithm
Lab 4 Solution – Configuring the Provider Core for MPLS The configuration below is for PE3. #-------------------------------------------------echo "OSPF Configuration" #-------------------------------------------------Configure router ospf traffic-engineering area 0.0.0.0 interface "P3-P1" exit interface "P3-P2" exit interface “P3-P4 exit interface "system" exit interface "P3-PE3" exit exit exit #-------------------------------------------------echo "MPLS Configuration" #-------------------------------------------------configure router mpls interface "system" exit interface "P3-P1" exit interface "P3-P2" exit interface “P3-P4” exit exit all
Lab 4 - Answers to Exercise Questions 1a. Are Opaque LSAs supported on your P/PE router? Yes.
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1b. What does it mean if a router supports Opaque LSAs but TE support is disabled? A router can support Opaque LSAs even if TE is not enabled. A router will accept these LSAs and pass them on, but may not need to make use of them. 3a. How many Type 10 LSAs are being reported? Depends on output. 3b. What could be an explanation if at this point prior to enabling Traffic Engineering on your router, the number of Type 10 LSAs is not 0? Others in the class might have already enabled TE and this router is receiving them 5a. How many Type 10 LSAs do you see? Since you have enabled TE on your PE router, your P router should see one more Opaque LSA than it had before (again assuming that others in the room have not also enabled TE on their routers yet) 5b. Why has this value increased even though you have not enabled TE on this router? The number of Opaque LSAs has increased on your P router when you enabled TE on your PE router. This is because your P router supports Opaque LSAs even though TE has not been enabled. 9a. What is the LSA type number for “Area Opaque”? The LSA number for Area Opaque is 10. 9b. Why does the Area ID show up as 0.0.0.0? The area ID shows up as 0.0.0.0 since the Area ID is a 32 bit value being represented in dotted decimal notation. 9c. Which top-level TLV sub-type does the LSA contain, and what does it specify? The LSA contains the top-level TLV sub-type 1 which contains information about the router’s system interface. 10a. Write down the number of Type 10 LSAs now being reported. Depends on output. 10b. How many Type 10 LSAs should be discovered when everyone in the class has finished enabling Traffic Engineering? There should be a total of 8 Type 10 LSAs since there are 8 routers in the lab network.
Lab 4 - Answers to Review Questions 1.
Why must Traffic Engineering extensions be enabled on OSPF? To be able to compute paths based on additional constraints using CSPF it is necessary to enable Traffic Engineering extensions on OSPF. This enables the exchange of additional link attributes, such as bandwidth, and enables the construction of the Traffic Engineering Database (also known as the opaquedatabase).
2.
What additional information is advertised by the routers when Traffic Engineering is enabled on OSPF? Maximum bandwidth, Maximum Reservable bandwidth, Unreserved bandwidth, administrative group and traffic engineering metric.
3.
What type of LSA is used to carry this additional information and where is it stored? Type 10 Opaque LSAs.
4.
What happens to the LSA type used for TE extensions in a multi-area OSPF network?
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The scope of Type 10 LSAs is intra-area, which means an ABR will not forward Type 10 LSAs across different areas. The implication of this is that constrained path cannot be computed end-to-end across different areas, since the routers in one area will not have a complete view of the network in their TED. 5.
What is missing in the opaque database if MPLS has not been enabled on the routersâ&#x20AC;&#x2122; interfaces? The LSA top-level TLV sub-type 2 (Link) will not be contained in the TED if MPLS has not been enabled on interfaces. Thus, additional link attributes will not be advertised.
Lab 5 Solution â&#x20AC;&#x201C; CSPF Based LSPs and LSP Establishment The configuration below is for PE3. #-------------------------------------------------echo "MPLS Configuration" #-------------------------------------------------admin-group "xlink" 1 interface "system" exit interface "PE3-P3" exit path "loose" no shutdown exit lsp "toPE2-lsp1" to 10.10.10.242 rsvp-resv-style se cspf primary "loose" bandwidth 425 exit no shutdown exit lsp "toPE2-lsp2" to 10.10.10.242 cspf primary "loose" exclude "xlink" exit no shutdown exit lsp "toPE2-lsp3" to 10.10.10.242 cspf primary "loose" bandwidth 300 exit no shutdown exit no shutdown ----------------------------------------------
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Lab 5 Section 5.1 - Answers to Exercise Questions
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10a. What path does each LSP take? How come? On the PE and P routers, LSP1 takes the shortest path using the diagonal cross-link and consume a total of 850Mbps of bandwidth on the cross-link. On the PE and P routers, LSP2 takes the shortest path using the diagonal cross-link, even though it has been configured to exclude the admin-group ‘xlink’ to which the diagonal cross-link belongs. This is because CSPF has not been enabled, and therefore a regular SPF computation is performed to determine the path. On the PE and P routers, LSP3 is not successfully established. 10b. Why is LSP #3 down? On the PE and P routers, LSP3 is down with Failure Code: CACRejection. This is because CSPF has not been enabled, and therefore a regular SPF computation is performed to determine the least cost path, which uses the diagonal cross-link. However, there is insufficient bandwidth available on the diagonal cross-link to support the LSP (LSP requests 300Mbps, but only 150Mbps is available). 11a. What path does each LSP take now? Why? On the PE and P routers, LSP1 remains on the same path as before. On the PE and P routers, LSP2 takes either the clockwise or counter-clockwise path through the core, avoiding the cross-link. On the PE and P routers, LSP3 takes either the clockwise or counter-clockwise path through the core as there is not enough bandwidth on the diagonal cross-link to support the LSP. 12a. What is the reserved bandwidth on the PE router’s interface to P? What is the reserved bandwidth on the P router’s interface to the PE? How can the sum of the two exceed 1Gbps? The reserved bandwidth on the PE’s interface to the P router and vice-versa is 725Mbps. This is the total bandwidth from LSP1 (425Mbps) and LSP3 (300Mbps). LSPs are uni-directional, and hence, bandwidth reservation is made in one direction on the link. 14a. On the P router is the LSP re-signaled with the new bandwidth? Why? The LSP is not re-signaled with the new bandwidth requirement because the reservation style used is Fixed Filter. With FF, the new bandwidth requested is added to the total bandwidth already reserved on a particular interface when the router determines whether it has enough bandwidth to support the bandwidth change. Thus, in this case, the total bandwidth consumed on the diagonal cross-link is 850Mbps. The 150Mbps of available bandwidth is not enough to support the bandwidth request of 450Mbps. 15a. On the PE router is the LSP re-signaled with the new bandwidth? Why? The LSP is re-signaled with the new bandwidth requirement because the reservation style is Shared Explicit. With SE, the difference in the new bandwidth requirement is added to the total bandwidth already reserved on a particular interface when the router determines whether it has enough bandwidth to support the bandwidth change. Thus, in this case, the total bandwidth consumed on the diagonal crosslink is 850Mbps. The 150Mbps of available bandwidth is enough to support the additional bandwidth requirement of 25Mbps. 16a. What path is taken for the following LSPs? If no path is available, why not? • LSP 1 to diagonal P router excluding the admin-group xlink. Path either via clockwise or counter-clockwise P router. •
LSP 2 to counter-clockwise P router including the admin-group xlink.
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LSP cannot be established as there is no route which satisfies the constraints.
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•
LSP 3 to clockwise P router with bandwidth of 200Mbps. Path either via clockwise or counter-clockwise P router depending on available bandwidth.
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LSP 4 to diagonal P router with hop-limit of 3 and excluding the admin-group xlink Path either via clockwise or counter-clockwise P router.
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LSP 5 to diagonal P router with hop-limit of 1 and excluding the admin-group xlink LSP cannot be established as there is no route which satisfies the constraints.
•
LSP 6 to clockwise P router excluding the admin-group xlink and excluding the interface from your P router to the clockwise P router. Path via counter-clockwise P router.
Lab 5 Section 5.2 - Answers to Exercise Questions 5a. For the PATH messages what is the source and destination of the message? The source IP address is the address of the router originating the LSP. The destination IP address is the address of the router terminating the LSP. 5b. For the RESV messages what is the source and destination of the message? The IP destination address of a RESV message is the address of a previous-hop node, obtained from the path state. The IP source address is an address of the node that sent the message. 5c. Why is there an ERO object in the PATH message even though the path used is “totally loose”? Because CSPF is used to compute a constrained based path for the LSP, and once determined, the path is included in an ERO object in the PATH message. 5d. Why does the RRO object in the PATH message transmitted only contain one entry for the PE router and two entries for the P router? As the PATH message is forwarded, each router along the path adds the IP address of its egress interface to the RRO object. 5e. Identify the labels that are PUSHed, SWAPed and POPed for packets traveling along this LSP. Depends on output. 5f. Does the LSP have a high priority for bumping other LSPs? The default pre-emptive priority of LSPs on the 7x50s is 7, which indicates the lowest priority for bumping other LSPs.
Lab 5 - Answers to Review Questions 1.
What constraints does the 7x50 take into consideration for LSP path computation? Bandwidth, hop count and admin-groups.
2.
What happens if the CSPF configuration is omitted from a LSP configured with a particular bandwidth requirement or admin-group inclusion/exclusion? A regular SPF calculation will be performed to determine the least cost path to the destination, irrespective of the constraints specified. This can result in the LSP being routed over a link it should not be routed on, or it can result in the failure to establish the LSP.
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What is the difference in behavior when you change the bandwidth of a LSP configured with SE reservation style versus FF? With FF, the new bandwidth requested is added to the total bandwidth already reserved on a particular interface when the router determines whether it has enough bandwidth to support the bandwidth change. With SE, the difference in the new bandwidth requirement is added to the total bandwidth already reserved on a particular interface when the router determines whether it has enough bandwidth to support the bandwidth change.
Lab 6 Solution – Enabling Primary and Secondary LSP Tunnels This is the solution set for the first and second part of this lab which requires the student to configure both Primary and Secondary paths, and examine the results.
The configuration if for P3: #-------------------------------------------------echo "MPLS Configuration" #-------------------------------------------------Configure router mpls path "Primary_Path" hop 1 10.1.3.1 strict hop 2 10.1.2.2 strict no shutdown exit path "Secondary_Path" hop 1 10.2.3.1 loose no shutdown exit lsp "LSP-P3-P2" to 10.10.10.77 cspf primary "Primary_Path" exit secondary "Secondary_Path" standby exit no shutdown exit no shutdown exit
Lab 6 - Answers to Exercise Questions 1a. What is the difference between “Strict” and “Loose” paths? A Strict path requires the next hop address to be directly connected to the current router, whereas a Loose path hop makes use of the routing table to find the best path to the next hop address. 3a. Where do the transiting LSPs come from? From the LSPs created from the clockwise neighbor Pod. 3b. Where do the terminating LSPs come from? From the LSPs created from the diagonally connected neighbor Pod.
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4a. What is the operational state of the Primary path? The operational state of the Primary path should be “UP”.
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4b. What is the operational state of the Secondary path? Explain The operational state of the Secondary path should be “Down”. The operational state of the Secondary path is “Down” since this Secondary path is in “warm standby”. The LSP Head must signal the Secondary state in order to enable it and bring it into an “up” state. 5a. Which direction is the “In Interface” pointing to? The “In Interface” is pointing back towards your P router. 5b. Which direction is the “Out Interface” pointing to? The “Out Interface” is pointing downstream towards the next router in the path. 5c. Which router’s address is the “Previous Hop” Address? The “Previous Hop” address is the address of your P router interface leading to this router. 5d. Is there any difference in this output in Phase II? No. The secondary path does not traverse this router. 5e. In Phase III, do you see your LSP transiting on your neighbor’s P router? Why? No because of the link failure the Secondary path is used and the Primary path is down. 6a. Is there any difference in this output in Phase II? Yes, the Secondary path of the LSP also terminates on the destination router since it is pre-established when the ‘standby’ parameter is included in the configuration. 6b. Is there any difference in this output in Phase III? Yes, the Primary path of the LSP no longer appears, since it is down after the interface shutdown. 7a. How many RSVP sessions are there, and what LSPs do they correspond to? The router has one RSVP session for each established LSP path that originates, transits or terminates on it. 7b. What identifies the LSP and what identifies the path? The LSP is identified by the Tunnel ID, while each path associated with it is identified by the LSP ID.
Lab 6 - Answers to Review Questions 1.
Can you configure a Primary path with strict hops and a Secondary path with no hops specified? What can be a consequence of doing this? Yes. The Secondary path will be determined based on IGP shortest path and thus could potentially use some of the same resources (links or nodes) as the Primary path, in which case it will not be completely physically diverse. However, if a network failure affects both the Primary and Secondary paths, since the Secondary path is loose, the head=end router will recomputed another route for the Secondary path, if one exists.
2.
Do the Primary and Secondary paths of a LSP use the same label at the destination router? No. Each LSP path is signaled separately and therefore makes its own label requests.
3.
What is the difference between having a Secondary path that standby versus not standby? A Secondary path configured as standby is signaled and established and ready for use as soon as the Primary path fails. A Secondary path that is not in standby must first be signaled and established after the Primary path fails.
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Lab 7 Solution – FRR One-to-One Link Protection The configuration is for PE3: #-------------------------------------------------echo "MPLS Configuration" #-------------------------------------------------configure router mpls path "to-PE2" hop 1 10.48.1.1 strict hop 2 10.1.3.1 strict hop 3 10.1.2.2 strict hop 4 10.32.1.2 strict no shutdown exit lsp "LSP-to-PE2" to 10.10.10.78 cspf fast-reroute one-to-one exit primary "to-PE2" exit no shutdown exit no shutdown
Lab 7 - Answers to Exercise Questions 1a. How many Dynamic LSPs do you see on your PE router? There should be only 1 Dynamic LSP originating on your PE router at this point. 1b. How many Dynamic LSPs do you see on your P router? There should be 1 originating LSP (the LSP from your P to the diagonally connected P router) and 1 transiting LSP (from your PE to the PE router in the diagonally connected Pod). 2a. How many routers are showing Detour Available? There should be 2 routers showing Detour Available (the “@” symbol). 2b. Which router is showing a Detour Available? Your P router, and the P router connected to you clockwise, are both showing that Detour routes are available. 2c. How many routers are showing “Node Protect”? There should be 1 router showing “Node Protect” (the router with a “n” symbol) 4a. Which inbound interface is being used by the LSP you’ve configured? Which for Outbound? Depends on output. 4b. Which inbound interface is being used by the detour for the LSP you’ve configured? Which for Outbound? Depends on output. 4c. Is this node part of a “Node” or “Hop” detour for the LSP you’ve configured? How do you know?
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This router is being used by the detour as part of a Node protection. The address being used is the system address of the P router of the Pod in the counter clock-wise direction from your Pod (the router in transit). Also, the detour path defines the out interface as an interface leading away from the P node (the node being protected). 4d. For which LSPs are the other detours shown generated? The router contains detours from the LSPs created by other Pods. For example, if you are on P3 there are originating detours for the LSP from Pod4 to Pod1 (P4 to P1 and PE4 to PE1) and from Pod3 to Pod2 (P3 to P2 and PE3 to PE2), There are also terminating detours for LSPs from Pod2 to Pod3 (P2 to P3 and PE2 to PE3). There could also be a transiting detour for the LSP from Pod1 to Pod4 (P1 to P4 and PE1 to PE4). 4e. What changes in this output when the interface is shutdown and your LSP makes use of the detour? The detour status becomes Active and the LSP state is Down. 5a. Identify what LSPs are shown, to which LSP each detour shown belongs, and where these detours go. To be completed with instructor. Depends on output. Principle is same as for question 4d. 5b. Trace out the end-to-end path taken by your LSP, when the interface is shutdown and the detour is used. To be completed with instructor. Depends on output.
Lab 7 - Answers to Review Questions 1.
Does the label stack grow when a detour LSP is used? No.
2.
What happens when node protection is requested but a given router cannot find a path which avoids the nexthop node? The router will still attempt to compute a detour which avoids the next-hop link.
3.
How does each router compute its detour for a given LSP? The router determines the detour LSP by finding the least cost path to the destination router (i.e. termination point of the protected LSP) while avoiding the next hop node or link.
Lab 8 Solution â&#x20AC;&#x201C; FRR Facility Bypass The configuration is for PE3: #-------------------------------------------------echo "MPLS Configuration" #-------------------------------------------------Configure router mpls path "to-P2" hop 1 10.48.1.1 strict hop 2 10.1.3.1 strict hop 3 10.1.2.2 strict no shutdown exit lsp "LSP-to-PE2" to 10.10.10.78 cspf fast-reroute facility exit
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primary "to-PE2" exit no shutdown exit
Lab 8 - Answers to Exercise Questions 3a. Which routers are being used as Node backup? You should find that your P router is being used as the Node backup. 3b. Which router is being used as a Link backup? You should find that the router to your left (in the path) is providing Link Protection. 4a. Which LSPs do the bypass tunnels seen protect? The bypass-node tunnel protects the two LSPs you configured on your PE and P routers. The bypass-link tunnel protects the two LSPs configured on the P and PE routers in the Pod that is counter-clockwise from yours. 4b. What path does each bypass tunnel take? The bypass-node tunnel should follow the direct path to the diagonally connected P router. The bypasslink tunnel may either follow the path via the diagonally connected P router, or may follow the path back to the P router in the counter-clockwise Pod, since both paths have equal cost.
5a. What is the Downstream Label? This is the label that the next-hop node (for link protection) or next-next-hop node (for node protection) expects to see in the incoming packet’s MPLS header. 6a. Which router is the PLR? The PLR is the router in the “From” field (in this example 10.10.10.223, or P3) 6b. Which router is the MP? The MP is the router shown in the “To” field (in this example 10.2.4.2, or P2) 7a. What is the Reservation Style type of the Bypass tunnel? The reservation style of the bypass tunnel is Fixed Filter A bypass tunnel uses only 1 label to represent many Primary tunnels since label stacking is being used. 8a. Which LSPs transit your P router? The LSP from your PE router to the PE router in the diagonally connected Pod, the LSP from the PE router in the Pod that is counter-clockwise from yours, to the one that is clockwise from yours, and possibly the bypass-link tunnel from the P router that is in the Pod clockwise from yours.
Lab 8 - Answers to Review Questions 1.
Does the label stack grow when a bypass tunnel is used? Yes. When the labeled packet reaches the PLR and is forwarded into a bypass tunnel, the PLR PUSHes a new label corresponding to the bypass tunnel onto the stack.
2.
How does each router compute its detour for a given LSP? The router determines the bypass tunnel by finding the least cost path to the next-hop router (in the case of link protection) or the next-next-hop router (in the case of node protection) while avoiding the next hop node or link. If the path computed by the PLR intersects a router that is on the protected LSP’s
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original path, then the bypass tunnel terminates on that router, and does not terminate on the next-hop or next-next-hop router.
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3.
If an LSP with FRR facilities backup mode is created from your PE router to the PE router in the Pod that is clockwise from yours, will it be protected by the bypass tunnel created by your P router for the two LSPs created in this Lab? No, because the bypass tunnel created from the previous lab does node protection and thus avoids the clockwise Podâ&#x20AC;&#x2122;s P router entirely. Your P router will create a another bypass tunnel to avoid the next-hop link, to protect this LSP.
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