Observing Network Convergence

Objectives

• Connect and configure WAN connections
• Configure EIGRP to advertise specific networks
• Observe the convergence of the network through the CLI window when an interface is shut down and brought back up
• Examine the EIGRP packets in the Simulation Mode as the network converges

Background / Preparation

You have been provided a topology in which HQ, Branch1, Branch2, and Branch3 are pre-configured. A new router has been added to the topology (New_Branch) that is partially configured. You will need to connect New_Branch to HQ and Branch1, complete the configuration of the new router, and then examine the convergence of the network

Step 1: Connect and configure WAN connection on New_Branch router

1. Connect interface S0/0/0 on New_Branch to S0/1/1 on HQ (DCE)
2. Connect interface S0/0/1 on New_Branch to S0/1/1 on Branch1 (DCE)
3. Configure interface S0/0/0 with the IP address 172.16.3.218/30
4. Configure interface S0/0/1 with the IP address 172.16.3.221/30

Step 2: Configure EIGRP to advertise specific network on New_Branch router

1. Configure New_Branch with EIGRP and the autonomous system number 3
2. Advertise specifically the directly connected networks

Step 3: Observe the network convergence in the Realtime mode

1. While in the CLI window of New_Branch, you can observe the convergence in the Realtime mode. As the network converges you will see that EIGRP develops adjacencies.
2. After the network has converged, shut down interface S0/0/0 on New_Branch.
3. Observe the changes in the network
4. Bring interface S0/0/0 back up

Step 4: Observe the network convergence in the Simulation mode

1. Click on Simulation Mode
2. Set the Event List Filters to show only EIGRP packets
3. Go to CLI interface window of New_Branch
4. Shutdown the interface S0/0/1
5. Click on the Auto Capture / Play button to start the simulation
6. Re-open the CLI window and observe the affects
7. Allows the simulation to run for a brief period, then click the Auto Capture / Play button to pause the simulation
8. Examine some to the packets in the Event List

Step 5: Observe the affects of an interface being brought up

1. Re-start the simulation by clicking the Auto Capture / Play button again.
2. Bring interface S0/0/1 back up and observe the convergence through the CLI window, Event List, and topology
3. Stop the simulation

Reflection

1. What output was shown in the CLI window once EIGRP had converged?
2. When the WAN link between HQ and New_Branch went down, what happened to the EIGRP packets on the New LAN?