Re: BGP Config

I am not sure why/how AT&T are doing things on their side but by them
advertising the aggregate shouldnt affect the prepending.

Have you used some looking glass servers to check if your prepending is
still valid ?

CCIE # 23962

On Wed, Jan 5, 2011 at 10:12 AM, Timothy Chin <tim_at_1csol.com> wrote:

> I have done the pre-pending already as a precaution but it doesnt have
> any effect on AT&Ts side because they are aggregating the prefix. I was
> thinking possibly something similar to BGP conditional advertisement?
>
>
>
> Timothy Chin
>
>
>
> CCIE #23866
>
>
> ------------------------------
>
> *From:* Shaughn Smith [mailto:maniac.smg_at_gmail.com]
> *Sent:* Wednesday, January 05, 2011 2:54 AM
> *To:* Timothy Chin
> *Cc:* ccielab_at_groupstudy.com
> *Subject:* Re: BGP Config
>
>
>
> You could try AS Path pre-pending on the low bandwidth link, or you could
> ask AT&T to not aggregate and advertise the correct prefix and ask the
other
> ISP to advertise the aggregate.
>
>
>
> CCIE # 23962 (SP)
>
>
>
> On Wed, Jan 5, 2011 at 9:48 AM, Timothy Chin <tim_at_1csol.com> wrote:
>
> I've been working on a BGP configuration between one site multihomed to
> 2 ISPs. One ISP is basically a backup with a low bandwidth connection
> and the other ISP is AT&T. AT&T assigned the Class C and I am
> advertising the network. The problem is that AT&T is aggregating the
> block and since I am advertising the specific class C all incoming
> traffic is coming through the low bandwidth connection because of the
> longest match. I hate to say my BGP is a little rusty but how would I be
> able to conditionally advertise the longest match to the low bandwidth
> ISP so that all traffic comes through AT&T via the aggregate?
>
>
>
> Timothy Chin
>
> CCIE #23866
>
>
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Received on Wed Jan 05 2011 - 10:15:03 ART