2.7 Using IP Unnumbered
2.7.3 RIP with IP unnumbered configured properly
In this scenario, RIP has been properly configured with IP unnumbered. The examples show how to verify the proper configuration of IP unnumbered.

Displaying the Routes

In the output of the show ip route command from RouterA, you can see that RouterA has a route to 168.71.8.0. (see RouterA#show ip route 168.71.8.1 command output)

In the output of the show ip route command from RouterC, you can see that RouterC has a route to 168.71.5.0. (see RouterC#show ip route 168.71.5.1 command output)

Notice that in both of the previous routing tables, the last update from address is the same as the actual address used in the show ip route command. Note that the routing entry indicates that this is a subnetted Class B address and not a host route because the mask is 255.255.255.0. This is the expected behavior when IP unnumbered is configured correctly. If IP unnumbered had been configured incorrectly, the routing entry would have a host route mask of 255.255.255.255.