Subject: Question on GenID

From: Narayanan Vidya-CVN065 <[email-masked]>
Date: Wed, 20 Oct 1999 16:16:05 -0500

Hi,
I was reading the draft "PIM Neighbor Hello GenID Option" and had a question
on its operation. According to the draft, if the GenID in an incoming Hello
packet is different from the last time, then the DR will unicast its most
recent RP-Set information to the rebooted neighbor. If the rebooted neighbor
was the DR, the next highest IP address or DR priority neighbor will unicast
this information. 

Now, what if the rebooting router was just an intermediate router? That is,
it is neither the DR (the router is not on a multi-access LAN), nor the
BSR/CBSR/RP/CRP. In this case, when the router reboots, how will the genID
help in getting the latest RP-Set information? Which router would send this
to the rebooted router? If it has more than one PIM neighbor, will it get
multiple copies of the information? 

Thanks,
Vidya

---

From: Yunzhou Li <[email-masked]>
Date: Wed, 20 Oct 1999 17:41:50 -0400

Narayanan,

> multiple copies of the information? 

Yes, neighbors from all links will unicast the latest RP-Set information
to the rebooting router. At each instant, there is only a single copy of
RP-Set info over the PIM domain. In fact, the rebooting router will be 
able to identify if they are indentical copy by looking at the Fragment 
Tag in the Bootstrap message. If two neighbors happen to have distinct
copy, the RP-Set info should be able to converge in next Bootstrap cycle.

Thanks,
Yunzhou