diff --git a/vrrpd/vrrp.c b/vrrpd/vrrp.c index 5d97199f40..d22c245afe 100644 --- a/vrrpd/vrrp.c +++ b/vrrpd/vrrp.c @@ -1961,7 +1961,42 @@ void vrrp_if_address_add(struct interface *ifp) void vrrp_if_address_del(struct interface *ifp) { - vrrp_autoconfig_if_address_del(ifp); + /* + * Zebra is stupid and sends us address deletion notifications + * when any of the following condition sets are met: + * + * - IFF_UP && address deleted + * - IFF_UP -> !IFF_UP + * + * Note that the second one is nonsense, because Zebra behaves as + * though an interface going down means all the addresses on that + * interface got deleted. Which is a problem for autoconfig because all + * the addresses on an interface going away means the VRRP session goes + * to Initialize. However interfaces go down whenever we transition to + * Backup, so this effectively means that for autoconfigured instances + * we actually end up in Initialize whenever we try to go into Backup. + * + * Also, Zebra does NOT send us notifications when: + * - !IFF_UP && address deleted + * + * Which means if we're in backup and an address is deleted out from + * under us, we won't even know. + * + * The only solution here is to only resynchronize our address list + * when: + * + * - An interfaces comes up + * - An interface address is added + * - An interface address is deleted AND the interface is up + * + * Even though this is only a problem with autoconfig at the moment I'm + * papering over Zebra's braindead semantics here. Every piece of code + * in this function should be protected by a check that the interface + * is up. + */ + if (CHECK_FLAG(ifp->flags, IFF_UP)) { + vrrp_autoconfig_if_address_del(ifp); + } } /* Other ------------------------------------------------------------------- */