tree 00f5d62575cbc5eb4744179e21bf1ac5ccb63f55
parent 76764ddcf53fa4840993c395fdf383a47ad61e8e
author Paul Jakma <paul.jakma@hpe.com> 1447862454 +0000
committer Donald Sharp <sharpd@cumulusnetworks.com> 1449602184 -0500

bgpd: Implicit updates in BGP may require a withdrawal from zebra RIB

*  J Yu <jackiesyu@hotmail.com> noted a problem with bgpd of routes not
   having their nexthop updated correctly.

   Martin Winter <mwinter@opensourcerouting.org> pinned this down to the
   case where a BGP route is updated from one with a valid nexthop to an
   invalid next-hop, using a test tool. Once the problem occurs, the incorrect
   route may remain, even after further UPDATEs, so long as the nexthop in the
   zebra RIB does not match the BGP route's nexthop.

   Jacqueline Yu then pinned the issue down further to being due to bgpd
   sending the DELETE for the route to zebra with the new nexthop after a
   BGP UPDATE updates an existing route, but then is found to be invalid,
   and zebra not finding the route as it requires a match on all attributes.

* bgp_zebra.c: (bgp_zebra_withdraw) When deleting a prefix, we want it gone.
  Do not send additional matching attributes like the nexthop, which can
  only cause incorrect non-matches.
Acked-by: Donald Sharp <sharpd@cumulusnetworks.com>