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Re: two AS announce the same adress space

  • From: Mikael Abrahamsson
  • Date: Tue Aug 01 17:34:51 2000

On Tue, 1 Aug 2000, Mikael Abrahamsson wrote:

> What will break if two different ASes announce the exact same adress
> space?

I have gotten approx 10-12 replies to this privately, and would just like
to say thanks for all the good input.

To summarize:

This is not allowed during to RFC.
It is "best practice" not to do it.
Several people do it and report that it works well.

Some warn that some BGP implementations might drop the announcement.

end summary:

One of the reason to do this is because one would not want to "waste" AS
just because one wants to do a single multihoming. What will happen when
we run out of ASes? As far as I can see 1/4 of the AS space is now

Mikael Abrahamsson    email: [email protected]