Ubuntu - Networking - IPv6 - Unicast, anycast, multicast - IPv6 multicast - IPv6 multicast addresses: FF00::/8

All IPv6 multicast addresses share the prefix of FF00::/8.

The first octet is FF (1111 1111).
- This way you can tell at a glance if an IPv6 address is intended for multicast or not.
The second octet defines:
- the lifetime (0 for permanent multicast; 1 for temporary)
- and scope (1 for node, 2 for link, 5 for site, 8 for organization, and E for global scope).

The multicast address ends with the interface ID.