Chapter 2 IPv6 Address Configuration
The first byte of the address format is set to full-one, identifying it as a multicast address.
The multicast address occupies the entire 1/256 of the IPv6 address space. The other
parts except the first byte of the multicast address format contain the following three fields:
l
Flags field
This field consists of four single bit flags. Currently, only bit-4 is designated to indicate
that whether this address is a well-known multicast address designated by the Internet
numbering institution, or a temporary multicast address used in a specific occasion.
If this flag bit is set to zero, it indicates that this address is a well-known address. If
this flag bit is set to one, it indicates that this address is a temporary address. The
other three flag bits are reserved for future use. The initialization value is 0.
l
Scope field
This is a 4-bit field and is used to indicate the range of multicast. That is, whether
a multicast group only includes nodes within the same local network, the same site
or the same institution, or includes nodes that resides anywhere in the IPv6 global
address space. The possible values 4-bits value ranges from 0 to 15.
lists
the corresponding range.
Table 2-6 Multicast Scope Values
Hex
Decimal
Value
0
0
Reserved
1
1
Node-local range
2
2
Link-local range
3
3
Reserved
4
4
Management-local range
5
5
Site-local range
6
6
Unallocated
7
7
Unallocated
8
8
Institution-local range
9
9
Unallocated
10
A
Unallocated
11
B
Unallocated
12
C
Unallocated
13
D
Unallocated
14
E
Global range
15
F
Reserved
l
Group ID field
2-9
SJ-20140504150128-018|2014-05-10 (R1.0)
ZTE Proprietary and Confidential