[AG-TECH] IGMPv3, Source Specific Multicast, fully supported in Windows XP

Jay Beavers jbeavers at microsoft.com
Fri Aug 16 02:48:56 CDT 2002

Three sites, Foo, Bar, and Nee.  All are sending multicast data to the
same routable multicast group address.

Foo sends a SSM request to only get traffic from Bar.  Are the following

If Bar's edge devices support IGMPv3, no effect since it's traffic is
being requested.

If Nee's edge devices support IGMPv3 and Foo is the only requestor, then
the traffic won't leave Nee's network.  If Nee's edge doesn't support
IGMPv3, the traffic will go onto the backbone.

If Foo's edge devices support IGMPv3, then Nee's traffic will be
filtered at the Edge and will not reach Foo.

If the edge router for each site supports IGMPv3, if the goal is
reducing traffic over the backbone and across the Internet2 POP, does it
matter if the switches behind the edge router support IGMPv3?

-----Original Message-----
From: Bill Nickless [mailto:nickless at mcs.anl.gov] 
Sent: Thursday, August 15, 2002 10:36 PM
To: Jay Beavers
Cc: ag-tech at accessgrid.org
Subject: Re: [AG-TECH] IGMPv3, Source Specific Multicast, fully
supported in Windows XP

At 10:01 PM 8/15/2002 -0700, Jay Beavers wrote:

>Since I'm not a router bithead, can anyone give me a heads up if I
>expect SSM to "just work" between Internet2 nodes?  Or might there be 

Hi Jay,

To answer your specific question: the Internet2 Abilene network is ready

and capable of running SSM, and has been for well over a year.

That being said, the problem with SSM deployment revolves around the
for network edge devices like switches and routers to support IGMPv3.
difficult to find Ethernet switches that support IGMPv3, and they're not

the most economical choices.

In a strange inversion of the normal situation, the backbone is capable
SSM service well before the local area networks of the connected sites.
you can find a site that supports SSM/IGMPv3 locally, it's a pretty good

bet that they can do SSM with most all other similar sites.

Bill Nickless    http://www.mcs.anl.gov/people/nickless      +1 630 252
PGP:0E 0F 16 80 C5 B1 69 52 E1 44 1A A5 0E 1B 74 F7
nickless at mcs.anl.gov

More information about the ag-tech mailing list