❦ 2 décembre 2016 11:42 +0100, Vincent Bernat <bernat@luffy.cx> :
Therefore, BFD seems incompatible with graceful restart. The Juniper implementation has some provisions to make BFD and BGP graceful restart works together: [...]
After trying the Juniper implementation, I discovered that the behavior is consistent with BIRD: if BFD fails, the session is destroyed and no graceful restart is possible. The difference is that on JunOS, you have a separate bfdd process and therefore, you can gracefully restart the BGP process while keeping the BFD sessions up. Something not possible with BIRD. Restarting BIRD "fast" is not enough. The discriminator changes and therefore, the BFD session is detected as down. I suppose JunOS could consider this as a graceful restart, but that's not the case. So far, my only solution would be to have a move BFD into its own daemon. -- Don't stop at one bug. - The Elements of Programming Style (Kernighan & Plauger)