vyos@vyos# set interfaces tunnel tun0 encapsulation gre
vyos@vyos# set interfaces tunnel tun0 address 172.16.0.2/24
vyos@vyos# set interfaces tunnel tun0 description "Tunnel to R1"
vyos@vyos# set interfaces tunnel tun0 mtu 1400
vyos@vyos# set interfaces tunnel tun0 policy route change-mss
vyos@vyos# set interfaces tunnel tun0 local-ip 2.2.2.10
vyos@vyos# set interfaces tunnel tun0 remote-ip 1.1.1.10
vyos@vyos# set interfaces tunnel tun0 multicast enable