Subject: RE: Pim-dm assert..

From: Sanjay Wadhwa <[email-masked]>
Date: Wed, 26 May 1999 09:18:13 -0400

The intent there was that the assert-loser should not 
respond with another assert when the assert-winner
does an assert after winning, since that is useless.
However, I am proposing that on the pruned interface 
assert should be replied to ONLY if you have a 
better metric than what you receive in the assert.

Thanks
Sanjay

> -----Original Message-----
> From: Gerhard Gessler [mailto:[email-masked]]
> Sent: Wednesday, May 26, 1999 3:23 AM
> To: PIM Mailing List
> Subject: Re: Pim-dm assert..
> 
> 
> Sanjay Wadhwa wrote:
> > 
> > Hi
> > I have a question on pim-dm assert mechanism.
> > Consider the following scenario :
> > 
> >                           S
> > 
> >                    |                |
> >                   A-L           A-W
> >                    |                |
> >               -------------------------------
> >                           |
> >                           D
> > 
> > Lets say the assert-winner gets established at time t.
> > The assert-loser will prune the interface to the lan till 
> time t+210.
> > Now if at time t+1 assert-winner loses route to the source.
> > The downstream router potentially may not get any data till t+209.
> 
> Thats right. 
> 
> > 
> > Does it make sense for the assert-winner in case it's route 
> to source is
> > lost,
> > to trigger an Assert with metric infinity, on (non-pruned) OIFs
> > in all (S,G) entries for this source. The assert loser will 
> receive an
> > Assert on the
> > pruned interface, and  since it's metric is better, can 
> respond with an
> > Assert,
> > and remove prune state on that interface.
> 
> The assert looser will not respond to this Assert Msg, because it
> arrives at a pruned interface. This is not in the spec but 
> you can find
> some statements about this in the mailing list archive (e.g. 
> "Assert on
> outgoing interface"  Mon, 09 Nov 98 19:27:00 PST from vishwas)
> 
> Hope this helps,
> 
>    Gerhard
> 
> -- 
> ---------------------------------------------------
> Gerhard Geßler
> 
> IABG mbH, Abteilung CS31
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