Subject: RE: interconnecting pim clouds with ipip tunneling

From: "Sundeep Singatwaria" <[email-masked]>
Date: Mon, 26 Mar 2001 13:35:15 -0800

-----Original Message-----
From: Pekka Savola [mailto:[email-masked]]
Sent: Monday, March 26, 2001 11:23 AM
To: pim
Subject: interconnecting pim clouds with ipip tunneling

Hello all,

Sorry if this is a wrong forum for this -- please tell of a better one if
this is the case.

DVMRP is not that good a solution for Internet multicasting; people rather
use PIM.  However, every upstream router has to be able to handle rather
recent versions of PIM for this to be an option.  Sometimes this just
can't happen.

Therefore I thought of using IPIP tunneling to establish virtual
connection with the PIM-enabled multicast domain.  This tunnel would only
be used for multicast traffic; no unicast routing would be done through
it.

You need to enable unicast routing to achieve this unless you have some 
other ingress - egress mapping mechanism to forward packet between the RP
and the tunnel termination end. 

Are there some flaws to this logic?  Has this kind of thing been done?
Successfully?  Any pointers?

As it is, I tried this quickly with FreeBSD 4.2 and pimd (PIMv2
sparse-mode) vs. Cisco 12.0; the link was established fine, I got
bootstrap and hello messages to flow in both directions but not much
else happened on the wire;  behind the tunnel, no multicast groups were
seen.

Please Cc: as I'm not on the list.  Thanks,
-- 
Pekka Savola                  "Tell me of difficulties surmounted,
Netcore Oy                    not those you stumble over and fall"
Systems. Networks. Security.   -- Robert Jordan: A Crown of Swords