The BGP Selective Address Tracking feature introduced the use of a route map with BGP fast session deactivation. The route-map keyword and map-name argument are used with the neighbor fall-over BGP neighbor session command to determine if a peering session with a BGP neighbor should be reset when a route to the BGP peer changes. The route map is evaluated against the new route, and if a deny statement is returned, the peer session is reset. The route map is not used for session establishment.
Sent from my iPhone On Jun 25, 2013, at 9:12 AM, Andrew Brant <[email protected]> wrote: > Fall-over combined with next hop tracking creates another distinct feature > called selective address tracking: > > The following commands are new or modified for this feature: > •bgp nexthop > •neighbor fall-over > http://www.cisco.com/en/US/docs/ios/12_4t/12_4t4/ht_bgpsn.html >>> neighbor 192.168.25.7 fall-over route-map RTM-BGP- >>> FALLOVER > > Cheers, > Andrew > > CCIE 14715 > > Sent from my iPhone > > On Jun 25, 2013, at 1:16 AM, Saku Ytti <[email protected]> wrote: > >> On (2013-06-24 23:19 -0500), Andrew Brant wrote: >> >>> neighbor 192.168.25.7 fall-over route-map RTM-BGP- >>> FALLOVER >> Fall-over and next-hop tracking are two distinct features. >> With next-hop tracking, you simply invalidate the next-hops there by >> invalidating the routes and choosing next-best option. >> With fall-over you tear down whole session, this is usually undesirably >> large hammer, consider your IGP flap is very short, if you tore down the >> iBGP it might take minutes to recover. >> >> But granted, if current version does not support selective next-hop >> resolution it seems like significantly better than nothing. >> >> >> -- >> ++ytti >> _______________________________________________ >> cisco-nsp mailing list [email protected] >> https://puck.nether.net/mailman/listinfo/cisco-nsp >> archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
