Do you have to use dynamic routing? Will static routing work? If so, use smcroute.
$ aptitude show smcroute Package: smcroute State: not installed Version: 0.93d-1 Priority: optional Section: net Maintainer: Julien BLACHE <[EMAIL PROTECTED]> Uncompressed Size: 69.6k Depends: libc6 (>= 2.3.6-6) Description: static multicast router daemon SMCRoute is a command line tool to manipulate the multicast routes of the Linux kernel. It can be used as an alternative to dynamic multicast routers like mrouted in situations where static multicast routes should be maintained and/or no proper IGMP signaling exists. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]