❦ 29 juillet 2020 12:13 +03, Saku Ytti: >> This is the solution Cumulus is advocating to its users, so I suppose >> they have some real users behind that. Juniper also supports RFC 5549 >> but, from the documentation, the forwarding part is done using >> lightweight tunnels. > > I'm not sure if you claim otherwise, but no real 'tunneling' takes > place, as far as I know, it's internal implementation detail having > IPV6 next-hop for IPV4. I don't think there is any additional headers > or any additional lookup or cost.
I didn't test, but the documentation states: > Starting in Release 17.3R1, Junos OS devices can forward IPv4 traffic > over an IPv6-only network, which generally cannot forward IPv4 > traffic. As described in RFC 5549, IPv4 traffic is tunneled from CPE > devices to IPv4-over-IPv6 gateways. These gateways are announced to > CPE devices through anycast addresses. The gateway devices then create > dynamic IPv4-over-IPv6 tunnels to remote customer premises equipment > and advertise IPv4 aggregate routes to steer traffic. Route reflectors > with programmable interfaces inject the tunnel information into the > network. The route reflectors are connected through IBGP to gateway > routers, which advertise the IPv4 addresses of host routes with IPv6 > addresses as the next hop. https://www.juniper.net/documentation/en_US/junos/topics/topic-map/multiprotocol-bgp.html#id-configuring-bgp-to-redistribute-ipv4-routes-with-ipv6-next-hop-addresses If you have a pointer around the subject on Juniper, I would be quite interested! Thanks. -- Write and test a big program in small pieces. - The Elements of Programming Style (Kernighan & Plauger)
