Tony, On Wed, May 09, 2012 at 02:12:05PM -0500, Tony Li wrote: > > On May 9, 2012, at 1:45 PM, Jeffrey Haas wrote: > > > Tony, > > > > On Wed, May 09, 2012 at 01:31:21PM -0500, Tony Li wrote: > >> One clarification: by "graceful shutdown" are you implying the use of > >> "graceful restart"? > > > > http://tools.ietf.org/html/draft-ietf-grow-bgp-gshut-03 > > > Thank you. This seems to indicate that after a g-shut event, the neighbor > would continue to advertise the prefixes to its peers (albeit tagged with the > community). Wouldn't this cause non-updated routers to blackhole traffic? > What happens when only half of you IBGP peers are updated? > > If the peering doesn't come back for an extended period, couldn't this cause > traffic to transit and then be blackholed, assuming there are no alternate > paths? > > This is violating BGP's fundamental principle: "Advertise what you're using, > use what you advertise." It seems like black holes are inevitable.
Please see the other clarification I posted. Graceful shutdown is applied to the routes from the peer that is sending bad updates that are accepted and valid. Routes that contain errors are processed with the stated "treat as withdraw" behavior. In other words, the goal is to remove the bad neighbor's valid routes from the forwarding path as much as possible since that neighbor is presumed to possibly crazy. -- Jeff _______________________________________________ GROW mailing list [email protected] https://www.ietf.org/mailman/listinfo/grow
