Source-specific multicast
Source-specific multicast is a method of sending multicasts in such a way that the recipient can choose the source (S, G). This can reduce the load on the network and improve security.
With the two protocols IGMPv3 (for IPv4 ) and MLDv2 (for IPv6 ), not only a group but also a special source can be selected instead of as with ASM . However, this requires the support of the last-hop router and the operating system. In IPv4, 16,777,216 addresses ( 232.0.0.0/8) are provided for this, in IPv6 the prefix is FF3x::/96responsible, which can be expanded to a / 32 network in the future .