-------- Forwarded message ----------
From: "Bob Sinclair" <bob@bobsinclair.net>
To: "Chris Atkins" <chris_atkins@blueyonder.co.uk>, <ccielab@groupstudy.com>
Date: Fri, 13 Jan 2006 19:34:59 -0500
Subject: Re: PIM Dense-Mode
Hi Chris,

To me, there are only two interesting kinds of problems in multicast:  RPF
problems and OILIST problems.  Seems to me your basic spoke-to-spoke multicast
issue is not an RPF problem, but an OILIST problem.

RPF problems arise when multicast arrives on an interface that is not
acceptable.  By default, the acceptable interface is that interface on the
shortest path to the source.  There are two ways to fix this kind of problem:
send the multicast on the acceptable interface, or make the interface on which
it is arriving acceptable.  There are two ways to make the interface
acceptable:  change the unicast routing table, or override it with a static
mroute.

OILIST problems arise from the rule that says "the incoming interface cannot
be on the outgoing interface list".  AFAIK, there is now way to multicast in
and back out of a multipoint frame interface using Dense Mode.  In order to
get multicast from spoke to spoke using Dense mode, you will have to tunnel
it.

HTH,

Bob Sinclair
CCIE #10427, CCSI 30427
www.netmasterclass.net