North American Network Operators Group|
Date Prev | Date Next |
Date Index |
Thread Index |
Author Index |
Re: honoring AS-path prepend from a peer or customer?
- From: Avi Freedman
- Date: Thu Feb 18 21:10:51 1999
In article <email@example.com> you wrote:
: If a peer (or transit customer) prepends their own AS to
: their route announcements to you, do you ever strip off
: the excessive As'es? That is, do you always honor them
: in your announcements to your other customers (or peers)?
: I do understand that any operator has full control over
: deciding his own outbound policy, regardless of the
: AS path.
: I want to know what the industry practice is and whether
: I should stipulate in my next upstream agreement that
: they honor my prepends?
Standard practice is to accept them, though you may need to tell
the peer or upstream what regexps to allow if they filter by as-path
as well as by prefix. (Always a good idea...)
My side question is - what shipping routers will let you rewrite
AS-Paths by doing anything other than just prepending? Just wondering
if any 7007-type horrors are lurking in the wings. I believe Criscos,
Bays, and gated boxes can't do this (without BGP->IGP->BGP redistribution).