Generic Routing Encapsulation (GRE)
Quand utiliser GRE ?

Configuration d'un tunnel GRE

R1(config)# interface Tunnel 0
R1(config-if)# tunnel mode gre ip
R1(config-if)# ip address 192.168.2.1 255.255.255.0
R1(config-if)# tunnel source 209.165.201.1
R1(config-if)# tunnel destination 198.133.219.97
R1(config-if)# router ospf 1
R1(config-router)# network 192.168.2.0 0.0.0.255 area 0
Verifiction du tunnel GRE
R1# show ip interface brief | include Tunnel
R1# show interface Tunnel 0