[86045] in North American Network Operators' Group
Re: The ORIGIN option on BGP - what is it for?
daemon@ATHENA.MIT.EDU (Sabri Berisha)
Fri Oct 21 08:39:54 2005
Date: Fri, 21 Oct 2005 14:37:30 +0200
From: Sabri Berisha <sabri@cluecentral.net>
To: Peter Boothe <peter@cs.uoregon.edu>
Cc: nanog@merit.edu
In-Reply-To: <Pine.SOL.4.58.0510202225030.18144@ix.cs.uoregon.edu>
Errors-To: owner-nanog@merit.edu
On Thu, Oct 20, 2005 at 10:34:35PM -0700, Peter Boothe wrote:
> So my question is: What do people use ORIGIN: EGP vs ORIGIN: IGP to
> distinguish? What makes a route EGP vs. IGP to you?
Origin is a mandatory transitive attribute which is being used in the
BGP decision algorithm.
If you have a prefix with the same localpref and aspath-length, the
decision will be made based on the lowest origin-value. IGP wins over
EGP, EGP wins over incomplete. You might use it to influence your
inbound traffic.
--
Sabri
please do not throw salami pizza away
