Multicast addresses with bit T of the flag field set to 0 correspond to permanent multicast addresses, assigned by IANA (Internet Assigned Number Authority)

When IPv6 multicast is widely deployed, we can imagine that some organisms will have some permanent broadcasts. Some TV channels or radio channels could be given the right to be allocated a permanent IPv6 multicast address derived from FF00::/12 multicast prefix.

RFC 2375 [RFC2375] defines the IPv6 multicast addresses already allocated. There are different kinds of “permanent” addresses. Some correspond to “low level” services (such as NTP, DHCP, cisco-rpannounce, SAP). The second kind corresponds to permanent “commercial” services (such as TV channels if they don’t use SSM). RFC 3307 [RFC3307] defines the allocation guidelines for the permanent addresses. It is described later in this chapter.