On Router 1, issue a ping command to the so-0/0/0 interface on Router 4 to send traffic across the IPSec tunnel.
user@R1> ping 10.1.56.2
PING 10.1.56.2 (10.1.56.2): 56 data bytes 64 bytes from 10.1.56.2: icmp_seq=0 ttl=254 time=1.351 ms 64 bytes from 10.1.56.2: icmp_seq=1 ttl=254 time=1.187 ms 64 bytes from 10.1.56.2: icmp_seq=2 ttl=254 time=1.172 ms 64 bytes from 10.1.56.2: icmp_seq=3 ttl=254 time=1.154 ms 64 bytes from 10.1.56.2: icmp_seq=4 ttl=254 time=1.156 ms ^C --- 10.1.56.2 ping statistics --- 5 packets transmitted, 5 packets received, 0% packet loss round-trip min/avg/max/stddev = 1.154/1.204/1.351/0.074 ms
If you ping the loopback address of Router 4, the operation succeeds because the address is part of the OSPF network configured on Router 4.
user@R1> ping 10.0.0.4
PING 10.0.0.4 (10.0.0.4): 56 data bytes 64 bytes from 10.0.0.4: icmp_seq=0 ttl=62 time=1.318 ms 64 bytes from 10.0.0.4: icmp_seq=1 ttl=62 time=1.084 ms 64 bytes from 10.0.0.4: icmp_seq=2 ttl=62 time=3.260 ms ^C --- 10.0.0.4 ping statistics --- 3 packets transmitted, 3 packets received, 0% packet loss round-trip min/avg/max/stddev = 1.084/1.887/3.260/0.975 ms