Upstream BGP community support

Richard A Steenbergen ras at e-gerbil.net
Sat Oct 31 23:27:38 UTC 2009


On Sun, Nov 01, 2009 at 12:00:20AM +0100, Andy B. wrote:
> I would not say that my upstream is an old stodgy network and
> certainly will I not consider them as "idiots", because they seem to
> know what they are doing. I'd rather say they are pretty ignorant when
> it comes to some "advanced" customer requirements.
> 
> By "they", I am referring myself to Hurricane Electric. But you are
> right: money should not be sent to them while they lack any kind of
> BGP community support.

Wow, really? I would never have guessed in a million years that HE would
have a problem supporting communities. Typically lack of community
support falls into one of two categories.

1) Old stodgy tier 1's who have communities but don't want to share them
with the world, because of silly NDA concerns or the like. This covers a
wide variety of positions, from "we won't export them to anyone" to "you
have to sign some paperwork and/or yell a lot to get the secret decoder
ring".

2) Those who lacks communities completely. IMHO both are idiots, but 
category #2 is a special breed which you should avoid like the plague. A 
common problem for service providers who lack communities is the 
inability to control their advertisements properly. Consider what 
happens when they have a multihomed customer who typically announces a 
prefix through them, but who decided to stop for some reason. They then 
end up hearing that prefix via some other route, such as a peer or 
transit provider, but without a community tag to know that it wasn't 
learned from a customer they will blindly readvertise it, providing 
unintentional (and typically unwanted) transit.

-- 
Richard A Steenbergen <ras at e-gerbil.net>       http://www.e-gerbil.net/ras
GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)




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