Consider the following example network:
In the network above we have three routers running RIP. Router R3 is connected to the ISP’s internet router and and has a static default route that points to it. It is possible to advertise that default route using RIP to other routers in the local network. On R3, we simply need to enter the default-information originate command in the RIP configuration mode.
Here is the configuration on R3:
R3(config)#ip route 0.0.0.0 0.0.0.0 18.104.22.168 R3(config)#router rip R3(config-router)#default-information originate
R1 and R2 don’t need any additional configuration – they learn the default route just like any other RIP route:
R1#show ip route rip R* 0.0.0.0/0 [120/1] via 10.0.0.1, 00:00:04, GigabitEthernet0/0
As you can see from the output above, R1 learned about the default route via RIP. The route is marked with an asterisk (*), indicating that the route is a candidate to be the default route.