Flags have 4 bits. The high-order flag is reserved, and must be initialized to 0.
T=0 indicates a permanently-assigned multicast address assigned by the Internet Assgined
Numbers Authority (IANA).
T=1 indicates a non-permanently-assigned multicast address.
Scope is a 4-bit value used to limit the scope of the multicast group. The values are as follows:
Value Indication
0、3、F reserved
1 Interface-Local scope
2 Link-Local scope
4 Admin-Local scope
5 Site-Local scope
6、7、9–D unassigned
8 Organization-local scope
E Global scope
Table 9-2 Indications of the Scope
Reserved Multicast Addresses:
Address Indication
FF01::1 All interface-local IPv6 nodes
FF02::1 All link-local IPv6 nodes
FF01::2 All interface-local IPv6 routers
FF02::2 All link-local IPv6 routers
FF05::2 All site-local IPv6 routers
FF0X:: X ranges from 0 to F. These multicast addresses are
reserved and shall never be assigned to any multicast
group.
Table 9-3 Reserved IPv6 Multicast Addresses
The solicited-node multicast address is a multicast group that corresponds to an IPv6 unicast or
anycast address. It is usually used for obtaining the Layer 2 link-layer addresses of neighboring
nodes within the local-link or applied in IPv6 Duplicate Address Detection. A node is required to
join the associated Solicited-Node multicast addresses for all unicast and anycast addresses that
have been configured for the node's interfaces.
IPv6 Solicited-Node Multicast Address Format:
FF02:0:0:0:0:1:FFXX:XXXX
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