nanog mailing list archives
Re: metric 0 vs 'no metric at all'
From: Pierfrancesco Caci <p.caci () seabone net>
Date: Tue, 03 Jan 2006 09:08:36 +0100
:-> "Alexander" == Alexander Koch <efraim () clues de> writes: > Hiya, > I was wondering if someone had done any or some research on > this before... basically I am not sure with all the many > implementations of BGP and all the vendors if and what those > will do when they see a metric of 0 and no metric. I am not > an expert knowing the actual protocol's messages exchanged, > but I see some routes with nothing in the metric field on > the various show commands, and some have explicit '0' metric. > I do not trust all the BGP implementations around, and we > consider changing the default outbound, with MEDs of course > still available on request. Cisco has a knob for this: http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123tcr/123tip2r/ip2_b1gt.htm#wp1076618 default is treating missing med as 0, which tends to surprise peers/customers who want to send med only on a few routes (i.e., if you want to set a med on a route, always set it on all your bgp sessions, because you can't tell if your neighbor has set "missing-as-worst" or not). Pf > Alexander -- ------------------------------------------------------------------------------- Pierfrancesco Caci | Network & System Administrator - INOC-DBA: 6762*PFC p.caci () seabone net | Telecom Italia Sparkle - http://etabeta.noc.seabone.net/ Linux paperino 2.4.20 #1 Mon Dec 2 17:02:14 CET 2002 i686 GNU/Linux
Current thread:
- metric 0 vs 'no metric at all' Alexander Koch (Jan 02)
- Re: metric 0 vs 'no metric at all' Daniel Roesen (Jan 03)
- Re: metric 0 vs 'no metric at all' Danny McPherson (Jan 03)
- Re: metric 0 vs 'no metric at all' Pierfrancesco Caci (Jan 03)
- Re: metric 0 vs 'no metric at all' Stephen J. Wilcox (Jan 03)
- Re: metric 0 vs 'no metric at all' Daniel Roesen (Jan 03)