[25312] in North American Network Operators' Group
Re: Global BGP community values?
daemon@ATHENA.MIT.EDU (Randy Bush)
Tue Oct 5 08:51:02 1999
From: Randy Bush <randy@psg.com>
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To: Alex Bligh <amb@gxn.net>
Cc: Vadim Antonov <avg@kotovnik.com>, hank@ibm.net.il,
nanog@merit.edu
Message-Id: <E11YU2H-0003Db-00@roam.psg.com>
Date: Tue, 05 Oct 1999 05:49:41 -0700
Errors-To: owner-nanog-outgoing@merit.edu
> Hank's suggestion requires no change to the BGP protocol in that
> use of communities which aren't known are ignored (i.e. won't
> break old speakers). But making speakers act on it requires
> changes to the implementation. In practice however, the fact
> inter-AS peerings do not normally have send-community enabled
> means that the information will often be dropped across the
> net without widescale changes.
>
> Your suggestion also requires no change to the BGP protocol in
> that use of optional transitive attributes which aren't known
> just results in them being ignored, so won't break old speakers.
> But making speakers act on it requires changes to the
> implementation. In practice however, the fact that non-fixed
> speakers may well drop the attribute means the information
> is likely to be dropped without widescale deployment of new
> code.
>
> Also, your scheme has another advantage over Hank's: The code
> changes to make Hank's scheme work are probably larger in
> various router vendor's code. Take Cisco: route-map handling
> of communities is really dumb. Let's say Hank's pref-prefix
> is (say) 1234:xxxx (where xxxx is the preference). You cannot
> easilly filter out 1234:anything and *just* drop that community
> from a string, and substitute in your own pref, nor do arithmetic
> operations (like add 5 to the pref). You can't even delete
> individual communities.
>
> I think better implement it properly.
what he said
but there is an underlying problem. i have a business relationship with my
direct neighbors under which we can negotiate traffic patterns. i do not
have a business relationship with a 'distant' network. hence i am rather
reluctant to allow them to influence my policies when those decisions my be
costing me money, or my customers performance, or ...
randy
