Upstream BGP community support

Joel Jaeggli joelja at
Mon Nov 2 19:33:49 UTC 2009

So this questions we have approached from time to time. Is there some
worth to be had in finding some consensus  (assuming such a thing is
possible) on a subset of the features that people use communities for
that could be standardized? particularly in the context of source based
remote triggered blackholing this seemed a like a worthwhile effort.

A standardized set means it can be cooked into documentation, training,
and potentially even products.

it doesn't mean that everyone will enable it, but if they do it would be
nice to agree on some basi grounds rules. it should also be understood
that many if not most localized community signaling uses would remain
localized in terms of their documentation and use.


jim deleskie wrote:
> Here is the problem as I see it.  Sure some % fo the people using BGP
> are bright nuff to use some upstreams communities, but sadly many are
> not.  So this ends up breaking one or more networks, who in turn twist
> more dials causing other changes.. rinse, wash and repeat.  But like
> Randy said who am I to stop anyone from playing... just means those of
> us with clue will be able to continue to earn a pay check for a very
> long time still :)
> -jim
> On Sat, Oct 31, 2009 at 9:25 PM, Randy Bush <randy at> wrote:
>> while i can understand folk's wanting to signal upstream using
>> communities, and i know it's all the rage.  one issue needs to be
>> raised.
>> bgp is a brilliant information hiding protocol.  policy is horribly
>> opaque.  complexity abounds.  and it has unfun consequences, e.g. see
>> tim on wedgies etc.
>> and this just adds to the complexity and opacity.
>> so i ain't sayin' don't do it.  after all, who would deny you the
>> ability to show off your bgp macho?
>> just try to minimize its use to only when you *really* need it.
>> randy

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