Subject: upstream neighbor ?

From: [email-masked]
Date: Tue, 17 Apr 2001 13:52:17 +0200

I have a little question:

In a Join/Prune message, it may exist both (*,G)Join and (S,G) in the same
message. But (*,G)Join are sent for RP and (S,G)Join are sent for S. So what is
the RPF neigbor address in the Join/Prune message? Is it RPF towards S or
towards RP.
And if the destination address of a Join/Prune is 224.0.0.13 (all PIM ROUTERS),
how does a router know if it must trigger a new Join message upstream (if it
receives Join message but it's not on the shortest path towards S or RP)?
Do Assert message deal with this ?

I hope I'm clear enough !
Thank you.

ALCATEL SPACE INDUSTRIES
Dép TS/AT/E
Tel : 33 (0)5 34 35 37 52  /  Fax : 33 (0)5 34 35 61 69
Porte : 2070  /  E-Mail : [email-masked]

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From: Bill Fenner <[email-masked]>
Date: Tue, 17 Apr 2001 12:22:37 -0700

>But (*,G)Join are sent for RP and (S,G)Join are sent for S. So what is

In the case that the RPF neighbors are different, you send two seperate
messages.

>And if the destination address of a Join/Prune is 224.0.0.13 (all PIM
>ROUTERS), how does a router know if it must trigger a new Join message
>upstream (if it receives Join message but it's not on the shortest path
>towards S or RP)?

The router that is identified in the "upstream neighbor address" field of
the Join/Prune message considers the Join/Prune message to be addressed
to it; other routers see the message for processing reasons but would not
trigger their own messages upstream.  Assert messages wouldn't normally
enter into this picture.

  Bill