Hi, On Tue, Nov 08, 2022 at 04:38:52PM +0000, Nick Hilliard wrote:
For example, on Linux, you can program the FIB in this way:
$ ip route add 192.0.2.0/24 via inet6 fe80::1 dev eth0
The 'eth0' interface does not need any IPv4 addresses assigned.
Right, ipv4 forwarding using ipv6 next hop resolution. Wow, that's ugly and likely to introduce an entirely new class of low-level forwarding bugs.
Cloud folks want this anyway, for configuring eBGP peers over link-local on p2p ethernets ("neighbour eth3 remote-as 12345"). Quite a few vendors can do this already. It's not that hard, actually, if the FIB is built "with L2 next-hop info right in the data structure" - when populating the FIB, you either do ARP or ND lookups, store the NH MAC + oif, done. Of course, getting support for this in my trusty 6500 won't be easy... (but vendor willing, even that one could learn to do it - this is pure control plane, and data plane punt if no L2 NH is known) Yeah. Multi-decade journey... Gert Doering -- NetMaster -- have you enabled IPv6 on something today...? SpaceNet AG Vorstand: Sebastian v. Bomhard, Michael Emmer Joseph-Dollinger-Bogen 14 Aufsichtsratsvors.: A. Grundner-Culemann D-80807 Muenchen HRB: 136055 (AG Muenchen) Tel: +49 (0)89/32356-444 USt-IdNr.: DE813185279