Enabling Multicast Connectivity Between Sites
Applies To: Windows Server 2008, Windows Server 2008 R2
An increasing number of organizations use multicast communication for such multiple-user applications as video conferencing, collaborative computing, and distance learning. Computers running Windows Server 2008 R2 or Windows Server 2008 can both send and receive IP multicast traffic. RRAS includes support for Internet Group Management Protocol (IGMP) as a routing protocol component, which you can configure with IGMP router mode and IGMP proxy mode to enable the exchange of multicast packets between remote sites. The IGMP Router and Proxy routing protocol is not itself a multicast routing protocol.
When you make your demand-dial routers multicast-capable, they can listen for all multicast traffic over all site-to-site connections, they can listen for IGMP Membership Report messages, and they can update the TCP/IP multicast forwarding table so that routers can determine where to forward incoming multicast traffic.
For a site-to-site connection, use the RRAS MMC snap-in to enable IGMP with IGMP proxy mode on the demand-dial interface on both the calling router and the answering router, and to enable IGMP with IGMP router mode on all other interfaces internal to the site.