From: Bob Sinclair (bob@bobsinclair.net)
Date: Mon Dec 10 2007 - 15:28:21 ART
Eric Phillips wrote:
> However, my question is does the source router continue to encapsulate the
> traffic after it is also sending the traffic using the (S,G) SPT?
Nope! Not suppose to.
> If the source
> router ceases encapsulating traffic in the PIM-Register message once the
> (S,G) is completed, why is a PIM-Register-Stop message even needed?
The RP only builds the S,G tree to the first hop router if the RP has an
interface on the OILIST for that group. If the RP has a null OILIST (no
one wants the traffic) then the Register stop is unicast back so that
traffic does not flow when not needed at all.
> Also, none of those sources seem to describe bi-directional PIM or SSM in
> any great detail, or describe how to implement and troubleshoot them; but
> both are on the blueprint.
The Doc CD configuration guide will be your best sources for
bidirectional and SSM. Bidirectional is like spanning-tree: the RP
designates a root device, ports are either RPF (think root port) or
Designated Forwarder (think designated port). If neither, ports block
for that group. No PIM registration at all. No S,G state at all.
First hop routers forward all traffic to the RP whether wanted or
not. BIDIR is NOT a substitute for NBMA-mode; the same packet does
not go in and out the same interface. Think switch flooding.
Lots of detail for SSM in the config guide. All S,G state. No *,G
state. No RP. Try to avoid getting lost in the URD and V3-Lite sections!
Hth,
--Bob Sinclair CCIE 10427 CCSI 30427 www.netmasterclass.net
This archive was generated by hypermail 2.1.4 : Tue Jan 01 2008 - 12:04:30 ARST