North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: Communities BCP [was: RE: BGP Path Filtering]
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 > >
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