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Re: Equal-cost path

Yasuhiro Ohara <yasu@SFC.WIDE.AD.JP> Tue, 12 April 2005 23:01 UTC

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From: Yasuhiro Ohara <yasu@SFC.WIDE.AD.JP>
Subject: Re: Equal-cost path
Comments: To: kireeti@JUNIPER.NET
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Ahahaha,
what are you talking about Kireeti !? ;p)

The correct answer would be "It's an implementation specific issue".

One should recognize ECMP as a property of OSPF (dijkstra) algorithm,
rather than a feature. It means "you can use either path as far as
those paths are equal cost". Which path to use actually is totally left
to the calculating router. Whichever the path is selected by the router
whole OSPF domain will work fine (in terms of issue regarding routing loops).

OSPF does not specify which path (out of ECMP) should be used/preferred,
it's totally left to a implementor.

regards,
yasu

From: Kireeti Kompella <kireeti@JUNIPER.NET>
Subject: Re: Equal-cost path
Date: Tue, 12 Apr 2005 15:40:29 -0700

> On Sun, 10 Apr 2005, Ilan Bercovich wrote:
> 
> > When not using "equal-cost multipath",
> > Which equal-cost path should be selected?
> 
> The one that's more equal than the rest.
> 
> Kireeti.
> -------
>

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