Re: BGP Allowas-in / Loop Prevention

You can trick the neighbor by advertising a different AS, using the neighbor
<IP> local-as <ASN> command. This will tell them you are in a different ASN
without having to change your entire BGP config.

Or, you can alternatively use AS Override, which is often used in MPLS on
the PE device to replace the CE ASN with the PE ASN. This preserves the
AS_PATH length but avoids getting caught by loop prevention.

On Wed, Mar 9, 2011 at 6:08 AM, Nish Vamadevan <ipnish_at_gmail.com> wrote:

> Hi,
>
> I have came across the allowas-in BGP command which will allow the AS
> number
> in when it is already in the AS-Path.
>
> What I am asking myself is... is there any other way of accomplishing the
> task other than redistributing into another routing protocol and taking it
> out?
>
> The reason I am asking is, Cisco has a tendency of asking questions on the
> lab and then specify "do not use this command"
>
> Any help will be appreciated.
>
> Thanks,
>
> --
> Regards,
> Nish
>
> http://twitter.com/nish
>
>
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Received on Wed Mar 09 2011 - 09:01:22 ART