OSPFv2 Enabler #3
In this latest OSPF Enabler exercise, you’ll configure a network of four routers with three areas. As always, the idea is simple: In one exercise, you’ll get to configure about 10 different OSPFv2 network commands, with different requirements for each. Just getting in some reps on some skills that need to be pretty much automatic for the CCNA exam!
Initial State: Topology and Area Design
Figure 1 shows the design for this exercise.
OSPF Enabler Topology
Initial State: Interfaces and Routing Protocol
Each of the three routers has an initial configuration that includes IPv4 addresses, working interfaces, and OSPFv2 configured with a router ID. Examples 1, 2, 3, and 4 show that configuration. (Note that you will reference this configuration when picking your answers.)6
int g0/1 ip addr 172.17.1.1 255.255.255.0 no shut ! int g0/2 ip addr 172.17.2.1 255.255.254.0 no shut ! int g0/3 ip addr 172.17.99.1 255.255.255.252 no shut ! int g0/4 ip addr 172.17.99.41 255.255.255.248 no shut ! int g0/5 ip addr 172.17.99.81 255.255.255.240 no shut ! router ospf 1 router-id 220.127.116.11 ! Need network Commands Here
Router R1 Initial Configuration
! int g0/1 ip addr 172.17.99.2 255.255.255.252 no shut ! int g0/2 ip addr 172.17.4.2 255.255.252.0 no shut ! router ospf 1 router-id 18.104.22.168 ! Need network Commands Here
Router R2 Initial Configuration
! int g0/1 ip addr 172.17.99.43 255.255.255.248 no shut ! int g0/2 ip addr 172.17.8.3 255.255.248.0 no shut ! router ospf 1 router-id 22.214.171.124 ! Need network Commands Here
Router R3 Initial Configuration
! int g0/1 ip addr 172.17.99.84 255.255.255.240 no shut ! int g0/2 ip addr 172.17.20.4 255.255.240.0 no shut ! router ospf 1 router-id 126.96.36.199 ! Need network Commands Here
Router R4 Initial Configuration
Your Job: Complete the Configuration with network Commands
To finish the configuration, you need to enable OSPF on all the interfaces shown in the figure. To do that, for this lab, add OSPFv2 network commands to each router’s configuration. (That is, purposefully do not use the ip ospf interface subcommand, so that you can practice the network command.)
By the end of this exercise, a real network with the combined initial config plus your config should result in:
- OSPFv2 neighbor relationships between each pair of neighboring routers. That means R1 will show three OSPF neighbors, and the other routers will list one neighbor.
- Each router has learned routes to all subnets in the figure
Configure Your Commands Per These Specific Rules
So far, the requirements would give you the ability to configure the network command in many ways. This section gives you specific requirements for this exercise just so that there is only one correct answer to the exercise. In your network commands, use wildcard mask parameters as follows:
R1 – Subnet wildcard: On router R1, use wildcard masks so that each network command would match all addresses in a single subnet.
R2 – Network wildcard: On router R2, use wildcard masks so that each network command would match all addresses in a single classful network (that is, in a single class A, B, or C network.)
R3 – Address wildcard: On router R3, use wildcard masks so that each network command would match one specific IP address.
R4 – Subnet wildcard: Same rules as router R1.
Note that this exercise is not like what real network engineers do in their jobs. For this exercise, I gave you different rules for the configuration of each router, so that you could exercise and learn different options. In real networks, you would probably use the same approach on each router.
I will post an answer post in a few days. So, look for the link at the bottom of this page.
Do this Exercise as a Lab with VIRL
Are you thinking that you’d like to just do this exercise with VIRL, instead of on paper, or just typing in an editor? We already built the topology and initial configuration. Just click below to get the .VIRL file.