Hi Burak, On Mon, Mar 16, 2009 at 12:06 AM, Burak Dikici <bdik...@gmail.com> wrote: > i am trying to use > BGP conditional advertisemet configuration. I have got a problem with > NON-EXIST route map's access-list. In the NON-EXIST router map i am using > the commands which is written below ;
Here are some notes I made recently when playing with BGP conditional advertising. I hope it helps. 1.) prefixes matched in advertise-map and exist/non-exist map must exist (or not) in the *BGP* table however: they do not need to be locally originated (e.g. R1 can match routes received from R2 and advertise (or not) to R3 and: the validity of the prefix in the BGP table (i.e. RIB-failure) doesn't matter. if there's there, and using exist-map, the condition is met. 2.) when using 'exist' map, prefixes matched by advertise-map are advertised when exist-map condition is met example: advertise 1.0.0.0/8 (advertise-map) from BGP table when 3.20.20.0/24 (exist-map) exists in BGP table 3.) when exist 'non-exist' map, prefixes matched by advertise-map are advertised when non-exist-map condition is met example: advertise 1.0.0.0/8 (advertise-map) from BGP table when 3.20.20.0/24 (non-exist-map) does NOT exist in BGP table 4.) prefixes matched in advertise-map are the only prefixes affected -- other prefixes that may exist are advertised (or not) as normal 5.) when dealing with conditional advertisement tasks, always consider what will happen normally (without any config) I'd be happy to be corrected, but I think the first point is contrary to what Ivan said. Also consider point #4 -- BGP conditional advertising is not strictly a route filtering mechanism, although it can be configured to achieve similar results. cheers, Dale _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/