Subject: Dr !!!

From: "Jyotheeswara Rao Kurma" <[email-masked]>
Date: Tue, 17 Apr 2001 11:58:17 +0500

Hi :

 I need a small clarification here regarding DR.

 Whenever a PIM router receives a IGMP v2 request from Host1 , it 
creates a (*,G) entry, but for a non-DR ( assuming several PIM-router 
on a single LAN)

                   RP
                 / \
              /      \
            DR      non-DR
             |       |
          ----------------------------
             |      |
             |      |
           Host-1 Router 1

pim_include() macro will be NULL, so oif-list() will be NULL, so it 
won't join the RP tree ( It(non-DR) won't send (*,G) joins towards RP)
Am I correct ?????

DR functionality is some thing like encapsulating initail multicast 
packets, and forward multicast as long as it is assert winner.
Am I correct ???

A router can forward packets only if it is either DR and didn't lost 
assert or it is assertwinner(no need of being DR) . Am I correct ???

What happens if downstram router Router-1 sends a (*,G) join towards 
RP. Now non-dr also joins RP tree I guess pim_include() macro will be 
not-null. And now I think Assert mechanism will come into picture.
because multiple RP tree paths to the same LAN.

One more thing is sneding Assert will not come, when there are only 
Directly connected members ( when no downstram PIM-Routers wish to join 
RP tree). 

Thanks,
Jyotheesh