Configure demand-dial routers for IP multicasting

1. For both the calling and the answering router, in the Routing and Remote Access snap-in, expand IP Routing, right-click General, click New Routing Protocol, and then click IGMP Router and Proxy.
   
2. Right-click IGMP, click New Interface, select the interface you want to enable, and then configure the interface as follows:
   
   
   1. Select Enable IGMP (the default), and then do the following:
      
      If this is the demand-dial interface, select IGMP proxy.
      
      If this is an intranet interface, select IGMP router.
      
   2. Typically, for IGMP protocol version, you can accept Version 3 (the default).
      
3. If needed, modify the default IGMP router settings. In most cases, no changes are needed.
   
   For more information about how to modify these settings, if analysis of your network indicates that you do need to modify them, see Configure IGMP router settings in Help and Support Center for Windows Server 2003