Now that we have configured GRE Tunnel, let us see how to check whether it is operational or not.
R1#sh ip int brief
Interface IP-Address OK? Method Status Protocol
Tunnel0 172.16.1.1 YES manual up up
R2#sh ip int brief
Interface IP-Address OK? Method Status Protocol
Tunnel0 172.16.1.2 YES manual up up
R1#sh int tun 0
Tunnel0 is up, line protocol is up
Hardware is Tunnel
Internet address is 172.16.1.1/24
MTU 1514 bytes, BW 9 Kbit, DLY 500000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation TUNNEL, loopback not set
Keepalive not set
Tunnel source 10.1.1.1, destination 10.1.1.2
Tunnel protocol/transport GRE/IP
Key disabled, sequencing disabled
Checksumming of packets disabled
Tunnel TTL 255
Fast tunneling enabled
Tunnel transmit bandwidth 8000 (kbps)
Tunnel...