Tunneling butuh 3 pasang IP.

First step is to create our tunnel interface on R1 and R2 :

R1	R2
R1(config)# interface Tunnel1 R1(config-if)# ip address 172.16.1.1 255.255.255.0 R1(config-if)# ip mtu 1400 R1(config-if)# ip tcp adjust-mss 1360 R1(config-if)# tunnel source 1.1.1.1 R1(config-if)# tunnel destination 2.2.2.2	R2(config)# interface Tunnel1 R2(config-if)# ip address 172.16.1.2 255.255.255.0 R2(config-if)# ip mtu 1400 R2(config-if)# ip tcp adjust-mss 1360 R2(config-if)# tunnel source 2.2.2.2 R2(config-if)# tunnel destination 1.1.1.1