Heads up: Long AS-sets announced in the next few days

Niels Bakker niels=nanog at bakker.net
Thu Mar 3 23:24:40 UTC 2005

* lorenzo at ripe.net (Lorenzo Colitti) [Fri 04 Mar 2005, 00:09 CET]:
> David Schwartz wrote:
>> Every piece of BGP documentation I have ever seen says that this 
>> attribute documents the ASes that the route has actually passed
>> through.
> I think the above paragraph of RFC 1771 disagrees with you.

Please quote properly; the context was AS_path, not AS_set.
David Schwartz was right on the mark here.

>> You certainly need their permission before you can advertise routes
>> that falsely came to have passed through their network! And yes, I
>> would argue that you do need permission to attach someone else's
>> community string to your routes and that it would be considered at
>> least terribly bad manners to use undocumented community strings from
>> other people's ASes. (Documentation, of course, equates to permission.)

This latter half is nonsense.  A community is a 32-bit number with no
guarantee of uniqueness; it's up to some kind-hearted fellow network
operators to act upon certain `magical' values (apart from well-known
ones as no-announce and no-export, of course) that they may have
described in an object's remarks in some IRR's database.  ASNs are
uniquely assigned to autonomous systems; preloading other AS_paths than
your own in an advertisement should be frowned upon (just like adding
fake Path: entries to your Usenet postings, or adding Received: headers
to e-mail if the e-mail in question did not pass through those systems).

	-- Niels.

                              The idle mind is the devil's playground

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