[58499] in North American Network Operators' Group
Communities BCP [was: RE: BGP Path Filtering]
daemon@ATHENA.MIT.EDU (Deepak Jain)
Fri May 16 14:51:46 2003
Reply-To: <deepak@ai.net>
From: "Deepak Jain" <deepak@ai.net>
To: "Jay Ford" <jay-ford@uiowa.edu>,
"Mark Radabaugh" <mark@amplex.net>
Cc: <nanog@merit.edu>
Date: Fri, 16 May 2003 14:50:09 -0400
In-Reply-To: <Pine.LNX.4.55.0305152316380.27527@seatpost.its.uiowa.edu>
Errors-To: owner-nanog-outgoing@merit.edu
> I like using BGP communities:
> o filter announcements you receive from downstreams based on your
> criteria of choice
> o set a specific BGP community (yourAS:whatever) on
> announcements which
> are to be propagated to various places (upstream providers, etc.)
> o do output filtering based on the communities you set
> Make sure you clear yourAS:whatever in announcements from your BGP peers.
>
> You can use this same technique for prefixes you originate, so
> that all your
> outbound BGP filtering is based on communities.
I am hijacking this thread a bit. Setting communities is excellent advice
especially if you are just starting out with downstream ASes.
The question is that changing your communities down the road might be a big
headache depending on whether you'll come to need more advanced ways of
filtering your announcements than coarse communities allow. Especially when
going (through growth or acquisition) from a single metro network to a
multi-metro or national/international one.
What criteria does the community think should be used when specifying
communities. IMO, overspecificity [sp?] doesn't hurt, but others may (and
have) disagreed. What's the BCP?
Thanks,
Deepak Jain
AINET
