Address
224.0.0.14
224.0.0.15
224.0.0.16
224.0.0.17
224.0.0.18
IPv6 multicast addresses
Figure 4 IPv6 multicast format
0
0xFF
Referring to Figure 4, the fields of an IPv6 multicast address indicate the following:
0xFF—Most significant eight bits are 11111111, indicating that this address is an IPv6 multicast
•
address.
•
Flags—Contains four bits.
Figure 5 Format of the Flags field
Table 4 Description of the Flags field bits
Bit
0
R
P
T
•
Scope—Contains four bits, which indicate the scope of the IPv6 internetwork for which the multicast
traffic is intended.
Description
RSVP encapsulation
All CBT routers
Designated SBM
All SBMs
VRRP
7
11
15
Flags
Scope
Group ID (112 bits)
Description
Reserved, set to 0.
•
When set to 0, it indicates that this address is an IPv6 multicast address without an
embedded RP address.
•
When set to 1, it indicates that this address is an IPv6 multicast address with an
embedded RP address (the P and T bits must also be set to 1).
•
When set to 0, it indicates that this address is an IPv6 multicast address not based on a
unicast prefix.
•
When set to 1, it indicates that this address is an IPv6 multicast address based on a
unicast prefix (the T bit must also be set to 1).
•
When set to 0, it indicates that this address is an IPv6 multicast address
permanently-assigned by IANA.
•
When set to 1, it indicates that this address is a transient, or dynamically assigned IPv6
multicast address.
7
31