1
6 (Link State Routing Protocol) 2 Static Routing Protocol Dynamic Routing Protocol Dynamic Routing Protocol (Link State Routing Protocol) OSPF (Open Shortest Path First) OSPF (Distance Vector Protocol) OSPF OSPF - OSPF OSPF - OSPF OSPF , , , NSSA - OSPF OSPF - IS-IS - IS-IS
6
• •
OSPF OSPF
•
OSPF OSPF , , , NSSA
•
OSPF OSPF
•
IS-IS
•
IS-IS
2
(OSPF) CCNA OSPF , OSPF OSPF OSPF OSPF IS-IS OSPF IS-IS www.sybex.com/go/CiscoProGuidetoInternetworking www.lammle.com
Link State Protocols (OSPF)
OSPF
IS-IS OSI IS-IS IS-IS OSPF OSPF (SPF) OSPF IS-IS
• (Hop) • • • VLSM (link state routing protocol ) • (Hop) • • •
30
• VLSM OSPF OSPF OSPF 6.1 6.2
3
6.1 OSPF
OSPF OSPF OSPF
6.1 OSPF
OSPF OSPF 0 1 ID IPv4 32 0 (backbone) 0.0.0.0. OSPF OSPF 0
6.1 OSPF
4
0
() OSPF
6.2
6.2 OSPF
OSPF ASBR
5
6.2 OSPF
RID (DR) (DR) (NBMA) DRs
(BDR) DR BDR DR DR OSPF RID DR
6
OSPF OSPF EIGRP EIGRP OSPF () 6.3 OSPF 6.3 OSPF
EIGRP , LSDB AS
6.3 OSPF
7
(LSU) (LSA) LSAs
() LSDB OSPF OSPF 5 5 OSPF IP OSPF TCP UDP OSPF TCP OSPF OSPF 5) IP OSPF 89 OSPF OSPF 6.4 6.4 IP OSPF
OSPF 2 OSPF 5 OSPF
OSPF OSPF
8
(MD5) ()
6.4 IP OSPF
(
(LSDB)
DBD) ( LSR)
IDs LSU
LSU
( LSU)
(LSA) LSA OSPF
( LSAac)
5 OSPF 6.5
9
6.5 OSPF () 1
Hello
6.5 OSPF () 2
DBD
3
LSR
4
LSU (LSA)
5
(LSA) (LSAs) 6.6 LSA 6.6 LSA ()
LSAac
10
1
6.6 LSA () 2
3
ABRs
4
ABRs ASBR
5
ASBR
(AS)
(AS) 6
LSAs OSPF
7
NSSA
NSSA ASBR NSSA
6.6 LSA
11
() 8
BGP
LSA
OSPF (BGP) 9
LSAs
9 , 10
LSAs 11 OSPF 10
OSPFTE LSAs RSVP-TE
11
LSAs
(MPLS) LSAs (AS) LSAs 11
LSDB AS ( 5) LSAs
6.6 LSA () LSAs
LSAs 11
9
12
1. 2. 3. LSAs 5 11 LSA LSA OSPF OSPF OSPF 1.
OSPF AS
2. DR/BDR DR 3.
LSDBs LSAs LSAs LSDBs OSPF LSAs
4. LSDB 5.
LSA
OSPF () OSPF OSPF OSPF IP 224.0.0.5 6.7 DR BDR DR BDR DR 6.7
32
IP
IP 192.168.15.1
13
192.168.1.1 LSU (DR) (BDR)
OSPF
6.7
4
OSPF
ID 8
14
6.7
DR BDR DR BDR
DR
XT
()
RIP OSPF (EIGRP) OSPF 18-24 EIGRP
BDR
15
OSPF 6.1 1. BangRtr1 OSPF DR 224.0.0.5
16
2. (BangRtr2,Bangrtr3 Bangrtr4 ) OSPF BangRtr1 BangRtr1 (init) 3. BangRtr2, BangRtr3 BangRtr4 BangRtr1 BangRtr1 4. BangRtr1 5.
DR BDR DR DR
“”
6. ( 10 ) DR,BDR 6.1
224.0.0.5
BangRtr1
BangRtr4 (RID) , (LSDB), OSPF, , (RID) RID DR
17
OSPF RID OSPF , RID RID 32 , , RID RID 1. ,
RID
2. (), RID
,
3. , , OSPF , RID ; RID , RID , RID – OSPF , OSPF , , (DR) , ,,, 1. BangRtr1 BangRtr2, BangRtr3, BangRtr4 2. BangRtr2 ,,, 3. BangRtr3 ,,, 4. BangRtr4 . 5. Pre-cutover Bangalore BangRtr1 DR
6.2 OSPF BangRtr1 BangRtr2, BangRtr3 BangRtr4 Gigabit Ethernet
18
6.2 Update DR propagated DR BangRtr3 DR BangRtr4 BDR DR BDR ( A B ) Adjacencies DR DR DR BDR 6.3
6.3 DR 1.
BangRtr1 BangRtr1 DR BDR DR BDR multicast 224.0.0.6 Bang Rtr1
2. DR BangRtr1 3. DR DR Multicast 224.0.0.5 DR BDR BDR DR 4. ( BangRtr2) DR
19
DR BDR
OSPF RID.
OSPF DR Hello Hellos inspects Hello packets DR BDR DR BDR. DR BDR
? DR .
" " RID. RID tiebreaker DR
RID
RID id RID 6.4 Lo0 interfaces.
6.4 DR Loopbacks
DR BDR .1 ,.10 ,.172 .192 BangRtr1 192 DR BangRtr2 .172 BDR 2 messed DR loopbacks DR. RID RID RID DR
broadcast network Loopback DR BDR. DR preempting no. Loopback DR DR failed. DR ,BDR BDR DR BDR
20
The Link State Database OSPF OSPF Hello Hello 2 Bidirectional Hello packet
LSDB DR BDR exstart Link State Internetwork Link State LSDBs.
State .
DR BDR adjacencies 1.
exstart, DR BDR adjacencies Master Slave DR BDR RID .
DR Master Slave 2.
DR RID DR Broadcase Master Slave
Slave-Master DBD State DBD LSA LSDB
LSA
Link state type Address of the advertising router Cost of the link Sequence number Link State Information Processing DBD DBD .
1.
DBD LSAck.
2.
DBD LSR link State LSRs Loading
3.
Link State LSU LSU LSAck.
4.
Link State LSDB
5.
LSRs .
State
21 LSDBs
Change Process OSPF Link State LSDBs Flooding LSUs Flooding LSAs.
DR. Flooding
1.
Link State multicast LSU LSA DRs OSPF BDRs. LSU LSU LSAs.
2. DR Flooding LSU multicast OSPF 224.0.0.5. LSU DR LSAck. Flooding LSA . 3. Flooding LSU LSU DR DR multicasts LSU 4.
LSDB LSU LSA. computes (SPF) . SPF, .
LSU
1.
LSA LSDB (LSAck) Flooding SPF
2. LSA LSA 3.
LSA LSDB LSAck
Flooding SPF
4. LSA LSU OSPF . Keeping the LSBD Current LSA
OSPF 30
LSA LSA LSU LSU LSA
LSA Link State
OSPF 30 LSDB Link State LSA Link State 60 60 LSDB.
LSDB
22
Link state sequence numbers Maximum age (maxage) Refresh timers OSPF LSA 32 leftmost 0x80000001 OSPF LSA 30
60 flooding incremented LSA LSA. LSA LSA 30
LSA LSA 0x80000001.
The Routing Table OSPF topology link State (LSA)
LSA propagates multicast 224.0.0.5. LSDB Link State State
LSA Link State (LSDB) LSA LSA .
SPF LSDB Tree SPF Tree SPF
Dijkstra Distance vector Precomputed
LSAs. Dijkstra
OSPF Cost OSPF interface. (100 Mbps) / (Bandwidth). 64-kbps link = 100,000,000/64,000 = 1,562 for a metric T1 link = 100,000,000/1,544,000 = 64 for a metric 100Mbps
23
100Mbps link = 100,000,000/100,000,000 = 1 for a metric OSPF interface. ip ospf interfacecost interface 1 - 65,535 . interfaces Gigabit 10Gigabit 1 interfaces 100Mbps bw bw Mb/s 1 - 4,294,967
OSPF drawbacks OSPF OSPF
OSPF
Drawbacks OSPF OSPF drawbacks Cost OSPF. topology OSPF topology OSPF.
OSPF Benefits Link State OSPF OSPF OSPF . OSPF drawbacks OSPF combated
IP Internetworks, Cisco 50 .
Link State Dijkstra LSAs Flooding LSDB Dijkstra OSPF IP packets. OSPF. OSPF 0 OSPF groupings
subtypes (NSSAs).
OSPF 2
0 OSPF OSPF 6.5
OSPF
6.5 Widget Line OSPF Area Structure
topology
24
Bangalore OSPF (, / )
Widget XT
6.5 .
6.5 1 2 3 0 1 2 0
Link State LSDB LSDB . adjacencies
OSPF .
OSPF Link Types OSPF 3
OSPF Point-to-Point
Broadcast
Ethernet
Non-broadcast Multi-access 2
multi-access (NBMA) ATM X.25. 5 OSPF NBMA point-to-point
Point-to-Point Point-to-point ( PP) serial T1
protocol (PPP) High-Level Data Link Control (HDLC) Layer 2 point-to-point multicasting packets Hello
OSPF multicast 224.0.0.5. point-to-point (DR) ( BDR) DR BDR OSPF Hello 10 40
Broadcast
25 Router OSPF Ethernet, FastEthernet Gigabit Ethernet DR BDR. Statut Link (LSDBs) adjacency Future Tech Hello DR BDR adjacencies DR BDR DR BDR broadcast
Non-broadcast Multi-access NBMA interface NBMA topology NBMA Full meshed multicast Frame, ATM X.25 NBMA Broadcast multicast NBMA multicast PVC processor ( CPU) bandwidth
OSPF NBMA
intensive OSPF Hello interfaces NBMA 30 120
NBMA PVCs SVCs topology ,NBMA OSPF
DR topologies NBMA DR BDR NBMA DR BDR adjacencies OSPF adjacencies
RFC 2,328, OSPF Topology NBMA.
Non-broadcast OSPF Broadcast DR BDR Full meshed. Point-to-Multipoint
Broadcash DR BDR meshed.
Non Broadcast point-to-multipoint Hello Flooding Broadcast point-to-multipoint Broadcast .
OSPF Cisco 3 Point-to-multipoint non-broadcast Broadcast Point-to-point OSPF 6.8
6.8 NBMA Network Mode Parameters (continued) Parameter
Description
26
point-to-multipoint
IP subnetMulticast OSPF Hello DR BDR-
LSAs
point-to-multipoint
multicast
non-broadcast
to multipoint
Hello
RFC
packets multicast; Cisco DR BDR
broadcast
WAN LAN IP subnet Multicast OSPF Hello
DR BDR topology
point-to-point
Subnet IP subinterface No DR BDR
LAN
adjacency interfaces WAN
Stub Areas stub area . Stub Area type-5 LSAs. OSPF Routers Stub Area ABRs Internal Routers configured stub routers neighbors Stub Area ABRs Default route Stub Area Stub Area: • ASBR Stub Area • Backbone Area Area 0
Area
27
• Virtual links Virtual links Configured Branch Offices Stub Areas Branch Offices OSPF Routing protocol Branch Offices Routers Routers Branch Offices Backbone Area Core Network HQ Stub Area Routers Stub Area Configured Stub Area LSAs area-id stub OSPF Routing configuration mode area-id Stub Area 6.6 Area Routers Configured
Totally Stubby Area Totally Stubby Area Cisco Totally Stubby Area Stub Area type-5 LSAs type-3 type4 LSAs ( Area) Area LSAs Totally Stubby Area Area Default Route 0.0.0.0 Stub Area. Totally Stubby Area Configured Stub Area. Totally Stubby Area Totally Stubby Area:
ABRs Default route Stub Area
Area
28
• OSPF Routers Totally Stubby Area Configured Stub Area Routers Routers Cisco Area • ABRs Routers Cisco Configured Totally Stubby Routers. ABRs Summary Routes Area • ASBR Totally Stubby Area • Backbone Area Area 0 • Virtual links Area • Virtual links Configured Stub Area. Totally Stubby Area Branch Offices
Routers
Internal Routers Totally Stubby Area Configured Stub Area Router LSAs area-id stub no-summary ABR Area Totally Stubby Area summary routes summary” routes 6.7 Area Routers Configured
Not So Stubby Area
no-summary Area “no
29
OSPF Not-So-Stubby Area (NSSA) Stub Area
NSSA ASBR Stub Area ABR
NSSA Area 0 NSSA ASBRs NSSA
FutureTech TechnoRama New York Office, Brach Office New York Office Configured Stub Area Dallas Headquaters Area 0 () RIP Branch Routers Stub Routers
WAN Link ( RIP) New York Office ( Stub
Area ) 6.8 Branch Office Area 1 FutureTech Network Area 0 RIP
New York Stub Area Routing Protocol ASBR ASBR Stub Area LSAs Stub Area Tpye-5 LSAs LSA
Area Type-5
30
Tpye-7 LSA ASBR Stub Area Area Not-So-Stub Area ASBR ASBR Type-7 LSAs Area Routers ABR Area 0 Type-7 LSAs Type-5 LSAs NSSA
NSSA. OSPF Routers NSSA ABRs Routers Configured NSSA Routers
Stub Area. NSSA ABRs Default route Stub Area
Area
NSSA • Backbone Area Area 0 • Virtual links Virtual links Configured • ASBR NSSA • NSSA LSAs Type-7 • Type-7 LSAs NSSA • NSSA ASBR Type-7 LSA NSSA ABR Type-5 LSA OSPF Domain Type-7 LSA O N2 O N1 (N NSSA). N1 external type-1 (E1). E1 cost OSPF Routed Network. N2 external type-2 (E2). E2 cost OSPF Routed Network O N2 Configuring OSPF OSPF
31
core routers OSPF • Area 0 • RnD1 RnD2 Area 1 • RnD3 RnD4 Area 2 OSPF Router router ospf process-id process-id OSPF Router Multiple OSPF Processes OSPF Router Multiple Processes Router network-id bit-mask area-id network-id IP Address bit-mask mask BangRtr1(config)#router ospf 1 BangRtr1(config-router)#network 10.0.0.1 0.0.0.0 area 0 BangRtr1(config-router)#network 10.0.0.5 0.0.0.0 area 1 BangRtr1(config-router)#network 10.0.0.9 0.0.0.0 area 1 BangRtr2(config)#router ospf 1 BangRtr2(config-router)#network 10.0.0.2 0.0.0.0 area 0
32
BangRtr2(config-router)#network 10.0.0.13 0.0.0.0 area 2 BangRtr2(config-router)#network 10.0.0.17 0.0.0.0 area 2 Router RnD core switch Area 1 Area 2 Routers Routers RnD WAN core interface Area 0 Routers RnD Area 0 Area WAN RnD1(config)#router ospf 1 RnD1(config-router)#network 10.0.0.6 0.0.0.0 area 1 RnD1(config-router)#network 10.1.0.1 0.0.0.0 area 1 RnD1(config-router)#network 10.1.1.1 0.0.0.0 area 1 RnD2(config)#router ospf 1 RnD2(config-router)#network 10.0.0.10 0.0.0.0 area 1 RnD2(config-router)#network 10.1.0.2 0.0.0.0 area 1 RnD2(config-router)#network 10.1.2.1 0.0.0.0 area 1 RnD3(config)#router ospf 1 RnD3(config-router)#network 10.2.0.1 0.0.0.0 area 2 RnD3(config-router)#network 10.0.0.14 0.0.0.0 area 2 RnD3(config-router)#network 10.2.1.1 0.0.0.0 area 2 RnD4(config)#router ospf 1 RnD4(config-router)#network 10.2.0.2 0.0.0.0 area 2 RnD4(config-router)#network 10.2.0.2 0.0.0.0 area 2 RnD4(config-router)#network 10.0.0.18 0.0.0.0 area 2 Area 1 Stub Area ABR Internal Routers Stub Routers Area 1 Stub BangRtr1 RnD1 RnD2 BangRtr1(config)#router ospf 1 BangRtr1(config-router)#area 1 stub
33
RnD1(config)#router ospf 1 RnD1(config-router)#area 1 stub RnD2(config)#router ospf 1 RnD2(config-router)#area 1 stub Area 2 Stub Area ABR Stub Area Internal Routers (RnD 3 4) Stub Routers area 2 stub no-summary RnD3(config)#router ospf 1 RnD3(config-router)#area 2 stub RnD4(config)#router ospf 1 RnD4(config-router)#area 2 stub NSSA area 2 nssa BangRtr2(config)#router ospf 1 BangRtr2(config-router)#area 2 nssa RnD3(BangRtr2(config)#router ospf 1 BangRtr2(config-router)#area 2 stub no-summary config)#router ospf 1 RnD3(config-router)#area 2 nssa RnD4(config)#router ospf 1 RnD4(config-router)#area 2 nssa OSPF BangRtr1#sh ip ospf neighbor
34
BangRtr1#sh ip ospf database
Last flood scan length is 2, maximum is 2 Last flood scan time is 0 msec, maximum is 8 msec Neighbor Count is 1, Adjacent neighbor count is 1 Adjacent with neighbor 10.1.1.1 (Backup Designated Router) Suppress hello for 0 neighbor(s) Here is the show ip ospf statistics output. BangRtr1#sh ip ospf statistics OSPF Router with ID (10.0.0.9) (Process ID 1) Area 0: SPF algorithm executed 5 times Area 1: SPF algorithm executed 10 times Summary OSPF SPF statistic SPF calculation time
Delta T Intra
D-Intra Summ D-Summ
Ext
D-Ext Total Reason
00:34:47 0
0
0
0
0
0
0
R, N,
35
00:33:53 0
0
0
0
0
0
0
R,
00:33:43 0
0
0
0
0
0
0
R,
00:32:24 0
0
0
0
0
0
0
R, N,
00:32:14 0
0
0
0
0
0
0
R, N,
00:32:04 0
0
0
0
0
0
0
R,
00:31:54 0
0
0
0
0
0
0
R,
00:30:23 0
0
0
0
0
0
0
X
00:30:01 0
0
0
0
0
0
0
X
00:28:05 0
0
0
0
0
0
0
X
RIB manipulation time during SPF (in msec): Delta T
RIB Update
RIB Delete
00:34:58
0
0
00:34:04
0
0
00:33:54
0
0
00:32:36
0
0
00:32:26
0
0
00:32:16
0
0
00:32:06
0
0
00:30:34
0
0
00:30:12
0
0
36
00:28:16
0
0
Here is the show ip ospf traffic output. BangRtr1#sh ip ospf traffic OSPF statistics: Rcvd: 698 total, 0 checksum errors 637 hello, 7 database desc, 3 link state req 26 link state updates, 25 link state acks Sent: 755 total 688 hello, 10 database desc, 1 link state req 39 link state updates, 18 link state acks OSPF Router with ID (10.0.0.9) (Process ID 1) OSPF queues statistic for process ID 1: OSPF Hello queue size 0, no limit, drops 0, max size 2 OSPF Router queue size 0, limit 200, drops 0, max size 2 Interface statistics: Interface FastEthernet0/20 OSPF packets received/sent Invalid
Hellos DB-des LS-req LS-upd LS-ack Total
Rx: 0
225
2
1
9
6
243
Tx: 0
231
3
0
9
8
251
37
OSPF header errors Length 0, Checksum 0, Version 0, Bad Source 0, No Virtual Link 0, Area Mismatch 0, No Sham Link 0, Self Originated 0, Duplicate ID 0, Hello 0 MTU Mismatch 0, Nbr Ignored 0, LLS 0, Authentication 0, OSPF LSA errors Type 0, Length 0, Data 0, Checksum 0, Interface FastEthernet0/2 OSPF packets received/sent Invalid
Hellos DB-des LS-req LS-upd LS-ack Total
Rx: 0
199
3
1
8
8
219
Tx: 0
229
4
1
14
5
253
OSPF header errors Length 0, Checksum 0, Version 0, Bad Source 0, No Virtual Link 0, Area Mismatch 0, No Sham Link 0, Self Originated 0, Duplicate ID 0, Hello 0, MTU Mismatch 0, Nbr Ignored 0, LLS 0, Authentication 0, OSPF LSA errors
38
Type 0, Length 0, Data 0, Checksum 0, Interface FastEthernet0/1 OSPF packets received/sent Invalid
Hellos DB-des LS-req LS-upd LS-ack Total
Rx: 0
213
2
1
9
11
236
Tx: 0
229
3
0
16
5
253
OSPF header errors Length 0, Checksum 0, Version 0, Bad Source 0, No Virtual Link 0, Area Mismatch 0, No Sham Link 0, Self Originated 0, Duplicate ID 0, Hello 0, MTU Mismatch 0, Nbr Ignored 0, LLS 0, Authentication 0, OSPF LSA errors Type 0, Length 0, Data 0, Checksum 0, Summary traffic statistics for process ID 1: Rcvd: 698 total, 0 errors 637 hello, 7 database desc, 3 link state req 26 link state upds, 25 link state acks, 0 invalid Sent: 757 total 689 hello, 10 database desc, 1 link state req
39
39 link state upds, 18 link state acks, 0 invalid IS-IS IS-IS OSPF OSPF IP OSPF IS-IS IS-IS ISPs IS-IS
Open Systems Interconnection (OSI)
IS-IS OSPF OSI IP IS-IS IS-IS IS-IS
IS-IS
IS-IS IS-IS
EIGRP
IS-IS MPLS BGP BGP IS-IS .
IS-IS IS-IS IS-IS IS-IS OSI IS-IS OSPF IS-IS Hello packet (LSPs) LSDB.
Dijkstra’s SPF LSDB
IS-IS 2 1 2 4 OSI Cisco
IS ES OSI , IS-IS , ES Cisco ES-IS protocol
ES ISS ES-IS ESs Hello packet Intermediate System Hello (ISH) ESs IS-IS IP OSI IP ICMP, ARP DHCP.
IS-IS Hello (IIH) ISS IS-IS IP ISS Connectionless Network Service (CLNS) IIHs. IS-IS IS-IS, CLNS Network Access Service Point (NSAP) IP NSAP
address NSAP IP IP
NSAP
NSAP link (LSPs) NSAP IS-IS IP
HEADER IP
NSAP 20 . 6.10 NSAP ADDRESS Cisco •
-
•
- ID
•
-NSEL
Cisco CLNS ISO 10,589 ISO NSAP
Figure 6,10 Cisco IS-IS (IDP) IDP IP classful IDP AFI IDI. (AFI) AFI 6.9 AFI
NSAP
IP
40
AFI 49 CLNS 49
(IDI) IDI AFI
IDI 47,0005 IDI 47,0006 .
(DSP) DSP IS-IS DSP (Ho-DSP) ID NSEL. (Ho-DSP) subnet IP. ID ID OSI OSI ECnet IP . NSEL NSEL IP NSEL . IS-IS NSAP IS-IS
• • ID • NSEL 1 AFI ID ID ID Cisco ID 6 U.S. Government OSI Profile (GOSIP) ID ID MAC address
ID .
NSEL NSEL 0 NSAP NSEL 0 Network Entity Title (NET) OSI Cisco 2 IS-IS 1 2 0 ES-IS 3 Inter-domain Routing Protocol (IDRP) 0 OSI ES-IS ESs ISH. ES ES 0 1. IS-IS (ESs) ISs 1 ( ID) cost path IS 2. 2 1 ISs 2 cost path
41
3 OSI 3 3 border gateway protocol (BGP)
IP 3 3 OSI Cisco Cisco Inter-domain
Routing Protocol (IDRP). IS-IS 3 1 2 1-2 1-2 ABRs OSPF IS-IS OSPF OSPF IS-IS • • VLSM • LSDB. • SPF . • ISP. • . Digital Equipment Corporation (DEC) IS-IS (DOD) OSPF (IETF) OSPF OSPF Protocol
1990 ISP IS-IS IP CLNS.
1980 Internet Engineering Task Force
42
Backbone Areas IS-IS Backbone Areas 2 1-2 IS-IS OSPF IS-IS OSPF ABR IS-IS
1 2 1-2 .
Update Exchange OSPF LSAs ( ) IS-IS link state packet (LSP)
IS-IS LSPs OSPF.
IS-IS OSPF IS-IS OSPF IS-IS
IS-IS CPU OSPF
OSPF LSA . IS-IS (TLV) TLV tuple IS-IS IS-IS . OSPF OSPF NSSA. OSPF 10 IS-IS IS-IS 6.11 IS-IS IS-IS Gure-Fi 6.11 IS-IS
6.11 IS-IS
43 [[
IS-IS . OSPF ISIS 0 MexRtr1(config)#router isis [area tag] NSAP NSAP NET MexRtr1(config-router)#net network-entity-title IS-IS IP CLNS . MexRtr1(config-if)#ip router isis [area tag] Cisco 1-2 MexRtr1(config-router)#is-type [-1 | -1-2 | -2-only] 1-2 interface. MexRtr1(config-if)#isis circuit-type [-1 | -1-2 | -2-only] 10 MexRtr1(config-if)#isis metric metric [delay-metric | expense-metric | errormetric] [-1 | -2] MexRtr1(config-router)#metric default-value [-1 | -2]
OSPF . OSPF
OSPF
IS-IS IS-IS OSPF OSPF IS-IS IS-IS