Hello Tony, Thanks for your email, yes community is best way to filter BGP session prefixes inside Backbone.
Regards, Ahmed On Fri, Apr 19, 2013 at 7:16 AM, Tony Tauber <[email protected]> wrote: > Explicit prefix-lists should be used at the PE (customer edge). > If some control is desired after that (or you foresee ever desiring same), > tag the routes inbound on the customer edge with communities and control > redistribution by filtering based on communities either internally or > outbound to other BGP neighbors. > > Tony > > > On Wed, Apr 17, 2013 at 3:35 PM, Ahmed Hilmy <[email protected]> wrote: > >> Hello Nick, >> >> Thanks for your reply, i am totally agree with you. >> >> Regards, >> Ahmed >> >> >> On Tue, Apr 16, 2013 at 9:12 PM, Nick Hilliard <[email protected]> wrote: >> >> > On 15/04/2013 21:44, Ahmed Hilmy wrote: >> > > I am using Prefix-list and as-path for BGP filter. >> > > But if i apply Prefix-list as inbound filter at PE, then from PE to >> RR ( >> > > Route Reflector ) i apply as-path filter, i think it is more scalable >> > than >> > > modify Prefix-list continuously ? or use community ? >> > > If my question not clear please ask me. >> > >> > it depends. >> > >> > Prefix lists are very fast because they are implemented as a trie, and >> it >> > is very fast to look up an entry in a trie. >> > >> > Community lists can be fast (standard, i.e. integer comparison) or slow >> > (extended, i.e. regular expression). >> > >> > as-path lists are slow because they use regular expressions. >> > >> > If you need to filter BGP updates, it is usually fastest to use prefix >> > lists or standard community lists. It makes little difference whether >> you >> > use extended communities or as-path lists - both are slow. >> > >> > Nick >> > >> > >> > _______________________________________________ >> > 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/ >> > > _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
