[c-nsp] Late night BGP puzzler

[Mike Leber]

The situations where this is most often used are where you are already
quashing the meds provided by both peers with your own internal traffic
engineering values.

If you were going to do that, a related useful command is "bgp
deterministic-med".

On Thu, 2 Aug 2007, Gunjan GANDHI (BR/EPA) wrote:

> MED should not be used under this scenario as both the upstream routes
> are from different providers. Unless both providers have agreed upon a
> MED benchmark value, it is not wise to use MED for route selection. It
> is like comparing oranges with apples.
> 
> Cheers
> //Gunjan
>  
> 
> -----Original Message-----
> From: cisco-nsp-bounces at puck.nether.net
> [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Collins, Richard
> (EXT)
> Sent: Thursday, 2 August 2007 11:24 AM
> To: cisco-nsp at puck.nether.net
> Subject: Re: [c-nsp] Late night BGP puzzler
> 
> 
>  What about using the command 'bgp always-compare-med' under the bgp
> router?
> If I understand this command then you can compare MED's between internal
> and externally learned routes instead of having 'best route' just going
> for external.
> 
> Rich
> 
> >Message: 1
> >Date: Wed, 01 Aug 2007 11:58:23 -0400
> >From: Jeff Fitzwater <jfitz at Princeton.EDU>
> >Subject: Re: [c-nsp] Late night BGP puzzler
> >To: "Metz, E.T. (Eduard)" <Eduard.Metz at tno.nl>
> >Cc: cisco-nsp at puck.nether.net
> >Message-ID: <46B0AD9F.3090005 at princeton.edu>
> >Content-Type: text/plain; charset=ISO-8859-1; format=flowed
> >
> >I set a MED value for each peer so that I can control which peer is
> used 
> >if they have equal paths.
> >
> >
> >Jeff Fitzwater
> >OIT Network Systems
> >Princeton University
> >
> >Metz, E.T. (Eduard) wrote:
> >> If I understand correctly, the cost-community is only considered very
> 
> >> late in the decision process (among others after as-path, med and
> >> e-bgp/i-bgp): 
> >>
> http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008009
> >> 4431.shtml
> >>
> >> All these should be equal before the cost-community kicks in..
> >>
> >> /Eduard
> >>
> >>   
> >>> -----Original Message-----
> >>> From: cisco-nsp-bounces at puck.nether.net 
> >>> [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Manu Chao
> >>> Sent: woensdag 1 augustus 2007 12:38
> >>> To: pkranz at unwiredltd.com
> >>> Cc: cisco-nsp at puck.nether.net
> >>> Subject: Re: [c-nsp] Late night BGP puzzler
> >>>
> >>> eBGP prefer to iBGP
> >>>
> >>> On 8/1/07, Peter Kranz <pkranz at unwiredltd.com> wrote:
> >>>     
> >>>> I can't for the life of me figure out why this won't select
> >>>>       
> >>> path #2 as
> >>>     
> >>>> the best path.. can someone unravel what I'm missing.. My
> >>>>       
> >>> goal is to
> >>>     
> >>>> get it to resolve the equal length AS path dispute usin
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