In this example we do observation only. You will see how I use RIPv1 to advertise "Default Route".
Making that happen depends on 2 keys:
- The "Default Route" should be already in R2's routing table.
- R2 is configured with "default-information originate" statement.
ip route 0.0.0.0 0.0.0.0 172.30.2.1
router rip
network 172.30.0.0
network 192.168.4.0
default-information originate
Then we can see the "Default Route" on R3:
R3>show ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route
Gateway of last resort is 192.168.4.2 to network 0.0.0.0
R 172.30.0.0/16 [120/1] via 192.168.4.2, 00:00:19, Serial0/0/0
C 192.168.4.0/24 is directly connected, Serial0/0/0
C 192.168.5.0/24 is directly connected, FastEthernet0/0
R* 0.0.0.0/0 [120/1] via 192.168.4.2, 00:00:19, Serial0/0/0
R3>