Конфигуриране на GRE тунел с устройства на Cisco

Примерна топология

Първоначална конфигурация

R1

enable
configure terminal
hostname R1
interface Gi0/0
ip address 11.0.0.1 255.0.0.0
no shutdown
interface Gi0/1
ip address 10.1.0.1 255.255.0.0
no shutdown
exit
router eigrp 101
network 11.0.0.0
end

R2

enable
configure terminal
hostname R2
interface Gi0/0
ip address 11.0.0.2 255.0.0.0
no shutdown
interface Gi0/1
ip address 12.0.0.2 255.0.0.0
no shutdown
exit
router eigrp 101
network 11.0.0.0
network 12.0.0.0
end

R3

enable
configure terminal
hostname R3
interface Gi0/0
ip address 12.0.0.2 255.0.0.0
no shutdown
interface Gi0/1
ip address 10.2.0.1 255.255.0.0
no shutdown
exit
router eigrp 101
network 12.0.0.0
end

GRE тунел

R1

enable
configure terminal

interface tunnel 0
tunnel mode gre ip
ip address 192.168.0.1 255.255.255.0
tunnel source 11.0.0.1
tunnel destination 12.0.0.1

end

Забележка: при задаване на tunnel source може да се използва и комбинацията tunnel source интерфейс, например tunnel source gi 0/0.