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H3C Technologies H3C S7500E Series Switches User Manual

Page 26

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Figure 1-4 IPv6 multicast format

Referring to

Figure 1-4

, 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

Figure 1-5

, 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

.

Table 1-5 Values of the Scope field

Value

Meaning

0, F

Reserved

1 Interface-local

scope