Re: as-override vs. allowas-in

Hi Scott,

Yeah, that was the only difference I could think of.

Well, on the technical side, as-override will replace the origin AS with the
MPLS cloud AS, while allowas-in will actually break the AS-PATH rule and
allow the AS to be repeated, so I guess that could impact filtering and some
other policy-related issues.

I wonder if the protocol will do some sanity-check on the AS-PATH and drop a
route that has a repeated AS inside, let's say, on a router in a connected
AS that receives this route.

On Fri, Jul 3, 2009 at 12:23 PM, Scott Morris <smorris_at_ine.com> wrote:

> I suppose it depends on your perspective. Purely technical, no, not
> really. They both allow the route to come in.
>
> Politically though, one you are solving on the SP side (presumably knowing
> more than your customers do), the other you are forcing all your customers
> to have different configurations with things they may not have a clue why.
>
> If you're doing managed CE routers, then there's no difference.
>
> My two cents.
>
>
>
>
> *Scott Morris*, CCIE*x4* (R&S/ISP-Dial/Security/Service Provider) #4713,
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> Persio Pucci wrote:
>
> Hi there,
>
> Is there any pratical difference on whether using "as-override" on the PE
> side instead of "allowas-in" on the CE when using BGP as the PE-CE protocol
> with two sites using the same AS#?
>
> Persio
>
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Received on Fri Jul 03 2009 - 14:41:42 ART