metric 0 vs 'no metric at all'
doug at ipath.net
Fri Feb 17 11:07:45 UTC 2006
And just to update, those drafts have made it into RFC 4271
From: owner-nanog at merit.edu [mailto:owner-nanog at merit.edu] On Behalf Of
Sent: Tuesday, January 03, 2006 3:49 PM
To: nanog at nanog.org
Subject: Re: metric 0 vs 'no metric at all'
On Jan 3, 2006, at 1:03 AM, Daniel Roesen wrote:
> So the spec is fuzzy about how "no MED vs. MED=0" should be
> treated, but
> vendors seem to largely agree to "no MED == MED 0". I know of no
> deviation, except the old ERX bug which got fixed (ERX treated "no
> as best, even better than MED=0 - contrary to documentation).
I recall some earlier implementations from "well known" vendors that
had varying behavior for MED processing as well.
Fortunately, the update to RFC 1771:
is considerably more explicit about this behavior, as well as a slew
of other previously-left-to-the-implementation items ironed out
through a great deal of implementation and deployment experience.
The "BGP Experience" and "BGP MED Considerations" Internet-
drafts provide a good bit of additional insight into some of these
More information about the NANOG