Reading: Finish me!
In this lab, you will configure a small network of three routers to use the OSPF version 2 routing protocol.
Using Packet Tracer, construct the following network:
| Device | Interface | IP Address | Subnet Mask | Default Gateway |
|---|---|---|---|---|
| R1 | G0/0 | 192.168.1.1 | 255.255.255.0 | N/A |
| S0/0/0 (DCE) | 192.168.12.1 | 255.255.255.252 | N/A | |
| S0/0/1 | 192.168.13.1 | 255.255.255.252 | N/A | |
| R2 | G0/0 | 192.168.2.1 | 255.255.255.0 | N/A |
| S0/0/0 | 192.168.12.2 | 255.255.255.252 | N/A | |
| S0/0/1 (DCE) | 192.168.23.1 | 255.255.255.252 | N/A | |
| R3 | G0/0 | 192.168.3.1 | 255.255.255.0 | N/A |
| S0/0/0 (DCE) | 192.168.13.2 | 255.255.255.252 | N/A | |
| S0/0/1 | 192.168.23.2 | 255.255.255.252 | N/A | |
| PC-A | FE0 | 192.168.1.3 | 255.255.255.0 | 192.168.1.1 |
| PC-B | FE0 | 192.168.2.3 | 255.255.255.0 | 192.168.2.1 |
| PC-C | FE0 | 192.168.3.3 | 255.255.255.0 | 192.168.3.1 |
As with the previous lab, use 1941 routers. You will need to install an HWIC-2T module into routers R1, R2, and R3 before you start configuring them. Be sure to install the module into slot 0 (on the right when looking at the back of the router). As usual, be careful to connect each line to the indicated interface.
The line connecting the PCs to the routers should be a crossover cable (dotted). However, using a straight-through cable, as shown in the diagram, should also work due to Cisco's adaptive interfaces.
As usual, configure the basic settings (Global Settings and Console Access; you do not need to configure remote access for this lab) on all the devices. Configure the network interfaces using the addresses shown in the addressing table.
Notice that all three serial connections require clock rate settings on the DCE side. Set the clock rate on the DCE side of the serial links to 128000 by using the clock rate 128000 command when configuring that interface.
Be sure to set appropriate default gateways on the PCs.
Demonstrate that each PC can ping all the interfaces on its router, and that the routers can ping each other. The PCs won't be able to communicate without routing information configured. That is normal.
Configure R1, R2, and R3 to use OSPF following the guideline in the slides. Use an OSPF process ID of 10 on all routers. Use manually specified router-ids of 1.1.1.1, 2.2.2.2, and 3.3.3.3 for R1, R2, and R3 respectively. Use the passive-interface command to disable OSPF on interfaces that do not need it. Be sure to record the commands you used for your report.
View the routing tables on all three routers. Does the information make sense?
Demonstrate that the PCs can all ping each other.
Use the show ip protocols command on all three routers. Does the information look reasonable? (Why?)
Configure a loopback interface on R1 with the IP address 172.16.0.1 with netmask 255.255.0.0. It can be a good practice to create a loopback interface on every router. This interface can be used as a destination address for remote access independent of the state of the router's other interfaces.
Remove R1's OSPF router ID (use "no" in front of the command you used to set the router ID), save the running configuration as the startup configuration, and then reboot the router using the reload command to force the change in router ID to take effect.
When the router reboots, do the following:
Verify that its OSPF router ID is now the address of the loopback interface.
Add the 172.16.0.0 network to OSPF routing.
Verify that router R3 knows about the 172.16.0.0 network via OSPF.
Configure remote access to R1 using SSH.
Verify that you can SSH to R1 from PC-C using the router's loopback interface address.
Be sure to record the commands you used for the above.
Create a loopback interface on R2 using the address 10.0.0.1 with netmask 255.0.0.0. We will use this loopback interface to simulate the Internet. Do not change the OSPF router ID for R2 (it should remain the manually specified ID of 2.2.2.2).
From R2, create a static route to network 0.0.0.0 0.0.0.0, using the ip route command as you did in previous labs, which forwards any traffic with an unknown destination out the loopback interface.
Configure OSPF on R2 to advertise the default route to the other routers by using the default-information originate command.
Finally, observe the routing tables on R1 and R3 to confirm the new gateway of last resort.
For this lab, submit your final Packet Tracer model, along with a document containing the commands you used to configure your devices, and your answers to the questions. The preferred document format is PDF, but Word, ODT, or plain text is also acceptable.
Last Revised: 2023-09-27
© Copyright 2023 by Peter Chapin <peter.chapin@vermontstate.edu>