nanog mailing list archives
Re: Communities BCP [was: RE: BGP Path Filtering]
From: Daniel Golding <dgold () FDFNet Net>
Date: Fri, 16 May 2003 14:13:56 -0500 (CDT)
To take a crack at it... - Route origin - customer, peer, transit provider, other (dial, etc) - Route geography - depends on your network, but some have seperate communities for POP, Country, Region, etc - Customer originated information - tweaks by your customers to selectively prepend, change local pref, not send to peers, or what not - Source AS - simply your AS:peer AS that the route was learned from There was an Internet Draft, last year, that summarized some of the approachs. I suspect overspecificity in this case has never done any harm, while lack of specificity has probably caused some heartache. - Daniel Golding On Fri, 16 May 2003, Deepak Jain wrote:
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
Current thread:
- BGP Path Filtering Mark Radabaugh (May 15)
- Re: BGP Path Filtering Brian Wallingford (May 15)
- Re: BGP Path Filtering Jay Ford (May 15)
- Communities BCP [was: RE: BGP Path Filtering] Deepak Jain (May 16)
- Re: Communities BCP [was: RE: BGP Path Filtering] Daniel Golding (May 16)
- Re: Communities BCP [was: RE: BGP Path Filtering] Joe Abley (May 16)
- Re: Communities BCP [was: RE: BGP Path Filtering] Jay Ford (May 16)
- Re: Communities BCP [was: RE: BGP Path Filtering] Danny McPherson (May 16)
- Re: Communities BCP [was: RE: BGP Path Filtering] Stephen J. Wilcox (May 16)
- Re: Communities BCP [was: RE: BGP Path Filtering] Danny McPherson (May 16)
- Re: Communities BCP [was: RE: BGP Path Filtering] Richard A Steenbergen (May 16)
- Re: Communities BCP [was: RE: BGP Path Filtering] Guy Tal (May 16)
- Re: Communities BCP [was: RE: BGP Path Filtering] Leo Bicknell (May 16)
- Re: Communities BCP [was: RE: BGP Path Filtering] Danny McPherson (May 16)
- Re: Communities BCP [was: RE: BGP Path Filtering] Danny McPherson (May 16)
- Communities BCP [was: RE: BGP Path Filtering] Deepak Jain (May 16)