H3C Technologies H3C S3100 Series Switches User Manual
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Figure 1-4 IPv6 multicast format
, the meanings of the fields of an IPv6 multicast address are as follows:
z
0xFF: The most significant 8 bits are 11111111, indicating that this address is an IPv6 multicast
address.
Figure 1-5 Format of the Flags field
z
Flags: Referring to
, the following table describes the four bits of the Flags field.
Table 1-4 Description on the bits of the Flags field
Bit
Description
0
Reserved, set to 0
R
z
When set to 0, it indicates that this address is an IPv6 multicast address without an
embedded RP address
z
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)
P
z
When set to 0, it indicates that this address is an IPv6 multicast address not based on a
unicast prefix
z
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)
T
z
When set to 0, it indicates that this address is an IPv6 multicast address
permanently-assigned by IANA
z
When set to 1, it indicates that this address is a transient, or dynamically assigned IPv6
multicast address
z
Scope: 4 bits, indicating the scope of the IPv6 internetwork for which the multicast traffic is intended.
Possible values of this field are given in
Table 1-5 Values of the Scope field
Value
Meaning
0, 3, F
Reserved
1 Interface-local
scope
2 Link-local
scope
4 Admin-local
scope
5
Site-local scope
6, 7, 9 through D
Unassigned
8 Organization-local
scope