Verifying the configuration

# Ping a router from the other router, for example, ping Router B from Router A.

[RouterA] ping 12.1.1.2
Ping 12.1.1.2 (12.1.1.2): 56 data bytes, press CTRL_C to break
56 bytes from 12.1.1.2: icmp_seq=0 ttl=254 time=2.137 ms
56 bytes from 12.1.1.2: icmp_seq=1 ttl=254 time=2.051 ms
56 bytes from 12.1.1.2: icmp_seq=2 ttl=254 time=1.996 ms
56 bytes from 12.1.1.2: icmp_seq=3 ttl=254 time=1.963 ms
56 bytes from 12.1.1.2: icmp_seq=4 ttl=254 time=1.991 ms

--- Ping statistics for 12.1.1.2 ---
5 packet(s) transmitted, 5 packet(s) received, 0.0% packet loss
round-trip min/avg/max/std-dev = 1.963/2.028/2.137/0.062 ms

The output shows that Router A can successfully ping Router B.