Subject: Join/Prune Messages

From: Narayanan Vidya-CVN065 <[email-masked]>
Date: Wed, 12 Jan 2000 11:02:17 -0600

Hello,
I have a question about the operation of Join/Prune Messages in PIM-SM.
According to the RFC, the PIM Join/Prune messages are multicast to the "ALL
PIM ROUTERS" group. However, in reality it is always sent to the unicast RPF
neighbor whose address is set to the target address inside the message. How
would unicasting this message make the operation of the protocol any
different? Would it change anything at all in the operation? 

Thanks,
Vidya

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From: Dave Thaler <[email-masked]>
Date: Wed, 12 Jan 2000 11:50:50 -0800 (PST)

> different? Would it change anything at all in the operation? 

Yes, it would cause black holes on LANs, since you wouldn't be able to
override prunes.  Search for "override" in RFC 2362.

On point-to-point links, it makes no difference either way.

-Dave