30
# Configure interface Serial 2/1/1 to borrow an IP address from GigabitEthernet 2/0/1.
[RouterB] interface serial 2/1/1
[RouterB-Serial2/1/1] ip address unnumbered interface gigabitethernet 2/0/1
[RouterB-Serial2/1/1] quit
# Configure a static route to the subnet attached to Router A, specifying Serial 2/1/1 as the
outgoing interface.
[RouterB] ip route-static 172.16.10.0 255.255.255.0 serial 2/1/1
Verifying the configuration
# Verify that a host attached to Router B can be pinged from Router A.
[RouterA] ping 172.16.20.2
Ping 172.16.20.2 (172.16.20.2): 56 data bytes, press CTRL_C to break
56 bytes from 172.16.20.2: icmp_seq=0 ttl=128 time=7.000 ms
56 bytes from 172.16.20.2: icmp_seq=1 ttl=128 time=2.000 ms
56 bytes from 172.16.20.2: icmp_seq=2 ttl=128 time=1.000 ms
56 bytes from 172.16.20.2: icmp_seq=3 ttl=128 time=1.000 ms
56 bytes from 172.16.20.2: icmp_seq=4 ttl=128 time=2.000 ms
--- Ping statistics for 172.16.20.2 ---
5 packet(s) transmitted, 5 packet(s) received, 0.0% packet loss
round-trip min/avg/max/std-dev = 1.000/2.600/7.000/2.245 ms