Let’s keep going and finish IPv6 introduction.
A multicast address identifies a group of interfaces. Traffic, that is sent to a multicast address, is sent to multiple destinations at the same time. An interface may belong to any number of multicast groups. Multicast addresses are defined by the prefix FF00::/8.
The second octet defines the flags and the scope of the multicast address. Flags can be defined as:
- 0 is reserved and must equal 0
- R indicates rendezvous point and is almost always set to 0
- P indicates prefix dependency and is almost always set to 0
- T is the temporary bit. For a temporary multicast address T equals 1; for a permanent multicast address T equals 0.