[c-nsp] BGP Multihomed Selective/Conditional Advertisement

[tkacprzynski at SpencerStuart.com]

So what would be the behavior if I set the community for Cogent to set
the Local Preference to 50 in terms of transit traffic? Does that mean
that Cogent's originated traffic would use ATT but Cogent's peers (with
a shorter AS path through Cogent) would still traverse Cogent even
though the lower local preference is there? I'm not sure about BGP's
behavior here or is that ISP specific configuration?

>>--Cogent
>>---Out 
>>----Internet access - my /24 advertise with Cogent's community set
Local preference something low like 50 (this >>way all Cogent users will
use the path through ATT avoiding Cogent's link. 


Thank you,


Tom


-----Original Message-----
From: Nathan [mailto:have.an.email at gmail.com] 
Sent: Monday, October 27, 2008 4:44 PM
To: Kacprzynski, Tomasz
Cc: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] BGP Multihomed Selective/Conditional Advertisement

On Mon, Oct 27, 2008 at 8:33 PM,  <tkacprzynski at spencerstuart.com>
wrote:
>
> What do you think about that configuration? The only thing I need to 
> check is if they will support a /32 to be advertised on their network.

Looks good to me except that you forgot prepends on Cogent Out Internet,
so that people who have a choice between Cogent and ATT don't send to
Cogent.

--
HTH,
Nathan