Proposal for L3VPN tunnel encapsulation

[pguibert6WIND]

This ticket is here to specify what would be the vty command look like, if someone wanted to rely on rfc5512.

vty example would rely on a locally configured interface.
this could be done by using route-map.

route-map rmap_to_apply_at_output 1
 set ip next-hop encapsulate l3vpn <InterfaceNAME>
 set ip[v6] next-hop encapsulate l3vpn <InterfaceNAME>
exit

[rwestphal]

Quick note: there's a draft [1] proposing to obsolete RFC 5512, and I believe this draft is on its way to be approved. It would probably be a good idea to take a look at this draft before doing any work based on RFC 5512.

[1] https://tools.ietf.org/html/draft-ietf-idr-tunnel-encaps-10