LAN WAN Laboratory 11 by Krit.P

Packet Tracer – Examining a Redundant Design Topology

Objectives Part 1: Check for STP Convergence Part 2: Examine the ARP Process Part 3: Test Redundancy in a Switched Network

Background In this activity, you will observe how STP operates, by default, and how it reacts when faults occur. Switches have been added to the network “out of the box”. Cisco switches can be connected to a network without any additional action required by the network administrator. For the purpose of this activity, the bridge priority was modified.

Part 1: Check for STP Convergence When STP is fully converged, the following conditions exist: All PCs have green link lights on the switched ports. Access layer switches have one forwarding uplink (green link) to a distribution layer switch and a blocking uplink (amber link) to a second distribution layer switch. Distribution layer switches have one forwarding uplink (green link) to a core layer switch and a blocking uplink (amber link) to another core layer switch.

Part 2: Examine the ARP Process Step 1: Switch to Simulation mode.

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Packet Tracer â&#x20AC;&#x201C; Examining a Redundant Design

Step 2: Ping from PC1 to PC6. a. Use the Add Simple PDU tool to create a PDU from PC1 to PC6. Verify that ARP and ICMP are selected in the Event List Filters. Click Capture/Forward to examine the ARP process as the switched network learns the MAC addresses of PC1 and PC6. Notice that all possible loops are stopped by blocking ports. For example, the ARP request from PC1 travels from A1 to D2 to C1 to D1 and then back to A1. However, because STP is blocking the link between A1 and D1, no loop occurs. b. Notice that the ARP reply from PC6 travels back along one path. Why? ____________________________________________________________________________________ c.

Record the loop-free path between PC1 and PC6. ___________________________________________

Step 3: Examine the ARP process again. a. Below the Scenario 0 drop-down list, click New to create Scenario 1. Examine the ARP process again by pinging between two different PCs. b. What part of the path changed from the last set of pings? ______________________________________

Part 3: Test Redundancy in a Switched Network Step 1: Delete the link between A1 and D2. Switch to Realtime mode. Delete the link between A1 and D2. It takes some time for STP to converge and establish a new, loop-free path. Because only A1 is affected, watch for the amber light on the link between A1 and D1 to change to green. You can click Fast Forward Time to accelerate the STP convergence process.

Step 2: Ping between PC1 and PC6. a. After the link between A1 and D1 is active (indicated by a green light), switch to Simulation mode and create Scenario 2. Ping between PC1 and PC6 again. b. Record the new loop-free path. __________________________________________________________

Step 3: Delete link between C1 and D3. a. Switch to Realtime mode. Notice that the links between D3 and D4 to C2 are amber. Delete the link between C1 and D3. It takes some time for STP to converge and establish a new, loop-free path. Watch the amber links on D3 and D4. You can click Fast Forward Time to accelerate the STP convergence process. b. Which link is now the active link to C2? ____________________________________________________

Step 4: Ping between PC1 and PC6. a. Switch to Simulation mode and create Scenario 3. Ping between PC1 and PC6. b. Record the new loop-free path. __________________________________________________________

Step 5: Delete D4. Switch to Realtime mode. Notice that A4, A5, and A6 are all forwarding traffic to D4. Delete D4. It takes some time for STP to converge and establish a new, loop-free path. Watch for the links between A4, A5, and A6 to D3 transition to forwarding (green). All three switches should now be forwarding to D3.

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Packet Tracer â&#x20AC;&#x201C; Examining a Redundant Design

Step 6: Ping between PC1 and PC6. a. Switch to Simulation mode and create Scenario 4. Ping between PC1 and PC6. b. Record the new loop-free path. __________________________________________________________ c.

What is unique about the new path that you have not seen before? ____________________________________________________________________________________

Step 7: Delete C1. Switch to Realtime mode. Notice that D1 and D2 are both forwarding traffic to C1. Delete C1. It takes some time for STP to converge and establish a new, loop-free path. Watch for the links between D1 and D2 to C2 to transition to forwarding (green). Once converged, both switches should now be forwarding to C2.

Step 8: Ping between PC1 and PC6. a. Switch to Simulation mode and create Scenario 5. Ping between PC1 and PC6. b. Record the new loop-free path. __________________________________________________________

Suggested Scoring Rubric Activity Section Part 2: Examine the ARP Process

Part 3: Test Redundancy in a Switched Network

Question Location

Possible Points

Step 2b

Step 2c

Step 3

Part 2 Total

Step 2

Step 3

Step 4

Step 6b

Step 6c

Step 8

Part 3 Total

Total Score

100

Earned Points

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Packet Tracer – Configuring PVST+ Topology

Addressing Table Device

Interface

IP Address

Subnet Mask

Default Gateway

VLAN 99

172.31.99.1

255.255.255.0

N/A

VLAN 99

172.31.99.2

255.255.255.0

N/A

VLAN 99

172.31.99.3

255.255.255.0

N/A

PC1

NIC

172.31.10.21

255.255.255.0

172.31.10.254

PC2

NIC

172.31.20.22

255.255.255.0

172.31.20.254

PC3

NIC

172.31.30.23

255.255.255.0

172.31.30.254

Switch Port Assignment Specifications Ports

Assignments

Network

S1 F0/6

VLAN 30

172.17.30.0/24

S2 F0/18

VLAN 20

172.17.20.0/24

S3 F0/11

VLAN 10

172.17.10.0/24

Objectives Part 1: Configure VLANs Part 2: Configure Spanning Tree PVST+ and Load Balancing Part 3: Configure PortFast and BPDU Guard

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Packet Tracer â&#x20AC;&#x201C; Configuring PVST+

Background In this activity, you will configure VLANs and trunks, and examine and configure the Spanning Tree Protocol primary and secondary root bridges. You will also optimize the switched topology using PVST+, PortFast, and BPDU guard.

Part 1: Configure VLANs Step 1: Enable the user ports on S1, S2, and S3 in access mode. Refer to the topology diagram to determine which switch ports (S1, S2, and S3) are activated for end-user device access. These three ports will be configured for access mode and enabled with the no shutdown command.

Step 2: Create VLANs. Using the appropriate command, create VLANs 10, 20, 30, 40, 50, 60, 70, 80, and 99 on all of the switches.

Step 3: Assign VLANs to switch ports. Port assignments are listed in the table at the beginning of the activity. Save your configurations after assigning switch ports to the VLANs.

Step 4: Verify the VLANs. Use the show vlan brief command on all switches to verify that all VLANs are registered in the VLAN table.

Step 5: Assign the trunks to native VLAN 99. Use the appropriate command to configure ports F0/1 to F0/4 on each switch as trunk ports, and assign these trunk ports to native VLAN 99.

Step 6: Configure the management interface on all three switches with an address. Verify that the switches are correctly configured by pinging between them.

Part 2: Configure Spanning Tree PVST+ and Load Balancing Because there is a separate instance of the spanning tree for every active VLAN, a separate root election is conducted for each instance. If the default switch priorities are used in root selection, the same root is elected for every spanning tree instance, as we have seen. This could lead to an inferior design. Some reasons to control the selection of the root switch include: The root switch is responsible for generating BPDUs for STP 802.1D and is the focal point for spanning tree to control traffic. The root switch must be capable of handling this additional load. The placement of the root defines the active switched paths in the network. Random placement is likely to lead to suboptimal paths. Ideally the root is in the distribution layer. Consider the topology used in this activity. Of the six trunks configured, only three are carrying traffic. While this prevents loops, it is a waste of resources. Because the root can be defined on the basis of the VLAN, you can have some ports blocking for one VLAN and forwarding for another. This is demonstrated below.

Step 1: Configure STP mode. Use the spanning-tree mode command to configure the switches so they use PVST as the STP mode.

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Packet Tracer â&#x20AC;&#x201C; Configuring PVST+

Step 2: Configure Spanning Tree PVST+ load balancing. a. Configure S1 to be the primary root for VLANs 1, 10, 30, 50, and 70. Configure S3 to be the primary root for VLANs 20, 40, 60, 80, and 99. Configure S2 to be the secondary root for all VLANs. b. Verify your configurations using the show spanning-tree command.

Part 3: Configure PortFast and BPDU Guard Step 1: Configure PortFast on the switches. PortFast causes a port to enter the forwarding state almost immediately by dramatically decreasing the time of the listening and learning states. PortFast minimizes the time it takes for the server or workstation to come online. Configure PortFast on the switch interfaces that are connected to PCs.

Step 2: Configure BPDU guard on the switches. The STP PortFast BPDU guard enhancement allows network designers to enforce the STP domain borders and keep the active topology predictable. The devices behind the ports that have STP PortFast enabled are unable to influence the STP topology. At the reception of BPDUs, the BPDU guard operation disables the port that has PortFast configured. The BPDU guard transitions the port into the err-disable state, and a message appears on the console. Configure BPDU guard on switch interfaces that are connected to PCs.

Step 3: Verify your configuration. Use the show running-configuration command to verify your configuration.

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Packet Tracer – Configuring Rapid PVST+ Topology

Addressing Table Device

Interface

IP Address

Subnet Mask

Default Gateway

VLAN 99

172.17.99.11

255.255.255.0

N/A

VLAN 99

172.17.99.12

255.255.255.0

N/A

VLAN 99

172.17.99.13

255.255.255.0

N/A

PC1

NIC

172.17.10.21

255.255.255.0

172.17.10.254

PC2

NIC

172.17.20.22

255.255.255.0

172.17.20.254

PC3

NIC

172.17.30.23

255.255.255.0

172.17.30.254

Switch Port Assignment Specifications Ports

Assignments

Network

S2 F0/6

VLAN 30

172.17.30.0/24

S2 F0/18

VLAN 20

172.17.20.0/24

S2 F0/11

VLAN 10

172.17.10.0/24

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Packet Tracer â&#x20AC;&#x201C; Configuring Rapid PVST+

Objectives Part 1: Configure VLANs Part 2: Configure Rapid Spanning Tree PVST+ Load balancing Part 3: Configure PortFast and BPDU Guard

Background In this activity, you will configure VLANs and trunks, Rapid Spanning Tree PVST+, primary and secondary root bridges, and examine the configuration results. You will also optimize the network by configuring PortFast, and BPDU Guard on edge ports.

Part 1: Configure VLANs Step 1: Enable the user ports on S2 in access mode. Refer to the topology diagram to determine which switch ports on S2 are activated for end-user device access. These three ports will be configured for access mode and enabled with the no shutdown command.

Step 2: Create VLANs. Using the appropriate command, create VLANs 10, 20, 30, 40, 50, 60, 70, 80, and 99 on all of the switches.

Step 3: Assign VLANs to switch ports. Port assignments are listed in the table at the beginning of the activity. Save your configurations after assigning switch ports to the VLANs.

Step 4: Verify the VLANs. Use the show vlan brief command on all switches to verify that all VLANs are registered in the VLAN table.

Step 5: Assign the trunks to native VLAN 99. Use the appropriate command to configure ports F0/1 to F0/4 on each switch as trunk ports and assign these trunk ports to native VLAN 99.

Step 6: Configure the management interface on all three switches with an address. Verify that the switches are correctly configured by pinging between them.

Part 2: Configure Rapid Spanning Tree PVST+ Load Balancing The Rapid Spanning Tree Protocol (RSTP; IEEE 802.1w) can be seen as an evolution of the 802.1D standard more so than a revolution. The 802.1D terminology remains primarily the same. Most parameters have been left unchanged so users familiar with 802.1D can rapidly configure the new protocol comfortably. In most cases, RSTP performs better than proprietary extensions of Cisco without any additional configuration. 802.1w can also revert back to 802.1D in order to interoperate with legacy bridges on a per-port basis.

Step 1: Configure STP mode. Use the spanning-tree mode command to configure the switches to use rapid PVST as the STP mode.

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Packet Tracer â&#x20AC;&#x201C; Configuring Rapid PVST+

Step 2: Configure Rapid Spanning Tree PVST+ load balancing. Configure S1 to be the primary root for VLANs 1, 10, 30, 50, and 70. Configure S3 to be the primary root for VLANs 20, 40, 60, 80, and 99. Configure S2 to be the secondary root for all of the VLANs. Verify your configurations by using the show spanning-tree command.

Part 3: Configure PortFast and BPDU Guard Step 1: Configuring PortFast on S2. PortFast causes a port to enter the forwarding state almost immediately by dramatically decreasing the time of the listening and learning states. PortFast minimizes the time it takes for the server or workstation to come online. Configure PortFast on S2 interfaces that are connected to PCs.

Step 2: Configuring BPDU Guard on S2. The STP PortFast BPDU Guard enhancement allows network designers to enforce the STP domain borders and keep the active topology predictable. The devices behind the ports that have STP PortFast enabled are not able to influence the STP topology. At the reception of BPDUs, the BPDU Guard operation disables the port that has PortFast configured. The BPDU Guard transitions the port into err-disable state, and a message appears on the console. Configure BPDU Guard on S2 interfaces that are connected to PCs.

Step 3: Verify your configuration. Use the show run command to verify your configuration.

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Packet Tracer â&#x20AC;&#x201C; Configuring EtherChannel Topology

Objectives Part 1: Configure Basic Switch Settings Part 2: Configure an EtherChannel with Cisco PAgP Part 3: Configure an 802.3ad LACP EtherChannel Part 4: Configure a Redundant EtherChannel Link

Background Three switches have just been installed. There are redundant uplinks between the switches. Usually, only one of these links could be used; otherwise, a bridging loop might occur. However, using only one link utilizes only half of the available bandwidth. EtherChannel allows up to eight redundant links to be bundled together into one logical link. In this lab, you will configure Port Aggregation Protocol (PAgP), a Cisco EtherChannel protocol, and Link Aggregation Control Protocol (LACP), an IEEE 802.3ad open standard version of EtherChannel.

Part 1: Configure Basic Switch Settings Step 1: Configure basic switch parameters. a. Assign each switch a hostname according to the topology diagram. b. Configure all required ports as trunks, depending on the connections between devices. Note: If the ports are configured with dynamic auto mode, and you do not set the mode of the ports to trunk, the links do not form trunks and remain access ports. The default mode on a 2960 switch is dynamic auto.

Part 2: Configure an EtherChannel with Cisco PAgP Note: When configuring EtherChannels, it is recommended to shut down the physical ports being grouped on both devices before configuring them into channel groups. Otherwise, the EtherChannel Misconfig Guard may place these ports into err-disabled state. The ports and port channels can be re-enabled after EtherChannel is configured.

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Packet Tracer â&#x20AC;&#x201C; Configuring EtherChannel

Step 1: Configure Port Channel 1. a. The first EtherChannel created for this activity aggregates ports F0/22 and F0/21 between S1 and S3. Use the show interfaces trunk command to ensure that you have an active trunk link for those two links. b. On both switches, add ports F0/21 and F0/22 to Port Channel 1 with the channel-group 1 mode desirable command. The mode desirable option enables the switch to actively negotiate to form a PAgP link. c.

Configure the logical interface to become a trunk by first entering the interface port-channel number command and then the switchport mode trunk command. Add this configuration to both switches.

Step 2: Verify Port Channel 1 status. a. Issue the show etherchannel summary command to verify that EtherChannel is working on both switches. This command displays the type of EtherChannel, the ports utilized, and port states. b. If the EtherChannel does not come up, shut down the physical interfaces on both ends of the EtherChannel and then bring them back up again. This involves using the shutdown command on those interfaces, followed by a no shutdown command a few seconds later. The show interfaces trunk and show spanning-tree commands also show the port channel as one logical link.

Part 3: Configure an 802.3ad LACP EtherChannel Step 1: Configure Port Channel 2. a. In 2000, the IEEE released 802.3ad, which is an open standard version of EtherChannel. Using the previous commands, configure the link between S1 and S2 on ports G0/1 and G0/2 as an LACP EtherChannel. You must use a different port channel number on S1 than 1, because you already used that in the previous step. To configure a port channel as LACP, use the interface configuration mode channel-group number mode active command. Active mode indicates that the switch actively tries to negotiate that link as LACP, as opposed to PAgP.

Step 2: Verify Port Channel 2 status. a. Use the show commands from Part 1 Step 2 to verify the status of Port Channel 2. Look for the protocol used by each port.

Part 4: Configure a Redundant EtherChannel Link Step 1: Configure Port Channel 3. There are various ways to enter the channel-group number mode command: S2(config)# interface range f0/23 - 24 S2(config-if-range)# channel-group 3 mode ? active auto desirable on passive

Enable Enable Enable Enable Enable

LACP unconditionally PAgP only if a PAgP device is detected PAgP unconditionally Etherchannel only LACP only if a LACP device is detected

a. On switch S2, add ports F0/23 and F0/24 to Port Channel 3 with the channel-group 3 mode passive command. The passive option indicates that you want the switch to use LACP only if another LACP device is detected. Statically configure Port Channel 3 as a trunk interface.

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Packet Tracer â&#x20AC;&#x201C; Configuring EtherChannel b. On switch S3, add ports F0/23 and F0/24 to Port Channel 3 with the channel-group 3 mode active command. The active option indicates that you want the switch to use LACP unconditionally. Statically configure Port Channel 3 as a trunk interface.

Step 2: Verify Port Channel 3 status. a. Use the show commands from Part 1 Step 2 to verify the status of Port Channel 3. Look for the protocol used by each port. b. Port Channel 2 is not operative because spanning tree protocol placed some ports into blocking mode. Unfortunately, those ports were Gigabit ports. To restore these ports, configure S1 to be primary root for VLAN 1 or set the priority to 24576.

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Packet Tracer â&#x20AC;&#x201C; Troubleshooting EtherChannel Topology

Objectives Part 1: Examine the Physical Layer and Correct Switch Port Mode Issues Part 2: Identify and Correct Port Channel Assignment Issues Part 3: Identify and Correct Port Channel Protocol Issues

Background Four switches were recently configured by a junior technician. Users are complaining that the network is running slow and would like you to investigate.

Part 1: Examine the Physical Layer and Correct Switch Port Mode Issues Step 1: Look for access ports. Examine the switches. When physical ports are assigned to an EtherChannel port, they behave as one. Each pair will either be operational or down. They will not be mixed with one port green and the other port orange.

Step 2: Set ports to trunking mode. a. Verify that all physical ports in the topology are set to trunking. Correct any that are in access mode. b. Correct any EtherChannel ports that are not set to trunking mode.

Part 2: Identify and Correct Port Channel Assignment Issues Step 1: Examine port channel assignments. The topology illustrates physical ports and their EtherChannel assignments. Verify that the switches are configured as indicated.

Step 2: Correct port channel assignments. Correct any switch ports that are not assigned to the correct EtherChannel port.

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Packet Tracer â&#x20AC;&#x201C; Troubleshooting EtherChannel

Part 3: Identify and Correct Port Channel Protocol Issues Step 1: Identify protocol issues. In 2000, the IEEE released 802.3ad (LACP), which is an open standard version of EtherChannel. For compatibility reasons, the network design team chose to use LACP across the network. All ports that participate in EtherChannel need to actively negotiate the link as LACP, as opposed to PAgP. Verify that the physical ports are configured as indicated.

Step 2: Correct Protocol issues. Correct any switch ports that are not negotiating using LACP.

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Packet Tracer â&#x20AC;&#x201C; Skills Integration Challenge Topology

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Packet Tracer â&#x20AC;&#x201C; Skills Integration Challenge

Addressing Table Device

Interface

IP Address

Subnet Mask

Default Gateway

VLAN Association

G0/0.1

192.168.99.1

255.255.255.0

N/A

VLAN 99

G0/0.10

192.168.10.1

255.255.255.0

N/A

VLAN 10

G0/0.20

192.168.20.1

255.255.255.0

N/A

VLAN 20

S0/0/0

209.165.22.222

255.255.255.224

N/A

S0/0/1

192.168.1.1

255.255.255.0

N/A

G0/0.1

192.168.99.2

255.255.255.0

N/A

VLAN 99

G0/0.10

192.168.10.2

255.255.255.0

N/A

VLAN 10

G0/0.20

192.168.20.2

255.255.255.0

N/A

VLAN 20

S0/0/0

192.168.1.2

255.255.255.0

N/A

S0/0/1

209.165.22.190

255.255.255.224

N/A

S0/0/0

209.165.22.193

255.255.255.224

N/A

S0/0/1

209.165.22.161

255.255.255.224

N/A

Web

NIC

64.104.13.130

255.255.255.252

64.104.13.129

N/A

PC10A

NIC

192.168.10.101

255.255.255.0

192.168.10.1

VLAN 10

PC10B

NIC

192.168.10.102

255.255.255.0

192.168.10.1

VLAN 10

PC20A

NIC

192.168.20.101

255.255.255.0

192.168.20.1

VLAN 20

PC20B

NIC

192.168.20.102

255.255.255.0

192.168.20.1

VLAN 20

ISP

Scenario In this activity, two routers are configured to communicate with each other. You are responsible for configuring subinterfaces to communicate with the switches. You will configure VLANs, trunking, and EtherChannel with PVST. The Internet devices are all preconfigured.

Requirements You are responsible for configuring routers R1 and R2 and switches S1, S2, S3, and S4. Note: Packet Tracer does not allow assigning point values less than 1. Since this activity is checking 154 items, not all configurations are assigned a point value. Click Check Results > Assessment Items to verify you correctly configured all 154 items. Inter-VLAN Routing On R1 and R2, enable and configure the subinterfaces with the following requirement: - Configure the appropriate dot1Q encapsulation. -

Configure VLAN 99 as the native VLAN.

Configure the IP address for the subinterface according to the Addressing Table.

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Packet Tracer – Skills Integration Challenge Routing Configure OSPFv2 using the following requirements: - User process ID 1. -

Advertise the network for each subinterface.

Disable OSPF updates for each subinterface.

VLANs For all switches, create VLAN 10, 20, and 99. Configure the following static ports for S1 and S2: -

F0/1 – 9 as access ports in VLAN 10.

F0/10 – 19 as access ports in VLAN 20.

F0/20 – F24 and G1/1 – 1/2 as the native trunk for VLAN 99.

Configure the following static ports for S3 and S4: -

F0/1 – 9 as access ports in VLAN 10.

F0/10 – 20 as access ports in VLAN 20.

F0/21 – F24 and G1/1 – 1/2 as the native trunk for VLAN 99.

EtherChannels All EtherChannels are configured as LACP. All EtherChannels are statically configured as the native trunk for VLAN 99. Use the following table to configure the appropriate switch ports to form EtherChannels: Port Channel

Device: Ports

S1: G1/1 – 2

S3: G1/1 – 2

S2: G1/1 – 2

S4: G1/1 – 2

S1: F0/23 – 24

S2: F0/23 – 24

S3: F0/23 – 24

S4: F0/23 – 24

S1: F0/21 – 22

S4: F0/21 – 22

S2: F0/21 – 22

S3: F0/21 - 22

Spanning Tree Configure per-VLAN rapid spanning tree mode for all switches. Configure spanning tree priorities according to the table below: Device

VLAN 10 Priority

VLAN 20 Priority

4096

8192

4096

32768

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Packet Tracer â&#x20AC;&#x201C; Skills Integration Challenge Connectivity All PCs should be able to ping the Web and other PCs.

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