On Sat, Mar 18, 2017 at 7:27 AM, Jeff Tantsura <jefftant@gmail.com> wrote:
That's only needed with label per VRF mode, and if I recall correctly in currently supported/discussed label per prefix mode where POP is followed by IP lookup in VRF context. IMHO - would be really bad (why repeat bad early IOS choices?) The most optimal case for FRR would be label per NH allocation, where label lookup should yield fully resolved adj, withno need for additional lookup. It would also support the case with >1 NH's in a VRF (multihoming).
There are some corner cases, like EIBGP LB + BGP FRR, however we are rather far away from that point in life...
Yes, pop+route lookup should not be mandatory for supporting l2/l3 vpns. But apparently Olivier needs this for his Segment Routing implementation, so I can't see why not support this in the Linux kernel. OpenBSD for instance allows pop+route lookup (OpenBGPD's l3vpn implementation relies on that because it allocates one label per VRF/rdomain). -- Renato Westphal