AS prepending

Fri Apr 8 14:34:05 UTC 2005

On Apr 8, 2005, at 10:28 AM, Philip Lavine wrote:

> I am using AS prepending to favor one ISP over
> another, in a BGP multihomed/multiISP scenario. Why
> does the ISP receiving the prepends fail to add my
> network into their routing table? Is this a "feature"
> of BGP, or have I gone too far with 3 prepend
> statements.

If they are both transit providers, then they are broken.

If they are peers, the second ISP is probably preferring the route it 
hears through your transit provider because there are fewer AS hops.

-- 
TTFN,
patrick