Vyatta Network OS Documentation

Learn how to install, configure and operate the Vyatta NOS, which helps drive our virtual networking & physical platforms portfolio.

Source-specific multicast

In Source-Specific Multicast (SSM), receivers are aware of sources. A receiver explicitly requests a stream from a sender in a group the receiver has joined, using a Join message that specifies the source (an (S, G) Join), and explicitly excludes the use of the wildcard for source—that is, it disallows the (*, G) Join.

Because SSM-enabled hosts track sources of the multicast transmission themselves, multicast routers do not need to discover the multicast sources themselves, and they need to store and maintain only the (*, G) state in the multicast routing table. This greatly reduces the burden on the multicast router.

For IPv4, the destination addresses must be in the range For IPv6, the addresses must be in the range FF3x::/96.

SSM is specified in RFC 3569, An Overview of Source-Specific Multicast (SSM) and RFC 4607, Source-Specific Multicast for IP.