389
Figure 123 IPv6 multicast address format
An IPv6 admin-scoped zone with a larger scope field value contains an IPv6 admin-scoped
zone with a smaller scope field value. The zone with the scope field value of E is the IPv6
global-scoped zone.
lists the possible values of the scope field.
Table 26 Values of the Scope field
Value
Meaning
Remarks
0, F
Reserved
N/A
1
Interface-local scope
N/A
2
Link-local scope
N/A
3
Subnet-local scope
IPv6 admin-scoped zone.
4
Admin-local scope
IPv6 admin-scoped zone.
5
Site-local scope
IPv6 admin-scoped zone.
6, 7, 9 through D
Unassigned
IPv6 admin-scoped zone.
8
Organization-local scope
IPv6 admin-scoped zone.
E
Global scope
IPv6 global-scoped zone.
IPv6 PIM-SSM overview
The ASM model includes IPv6 PIM-DM and IPv6 PIM-SM. The SSM model can be implemented by
leveraging part of the IPv6 PIM-SM technique. It is also called "IPv6 PIM-SSM."
The SSM model provides a solution for source-specific multicast. It maintains the relationship
between hosts and routers through MLDv2.
In actual applications, part of MLDv2 and IPv6 PIM-SM techniques are adopted to implement the
SSM model. In the SSM model, because receivers have located an IPv6 multicast source, no RP or
RPT is required. No source registration process is required for discovering IPv6 multicast sources in
other IPv6 PIM domains.
Neighbor discovery
IPv6 PIM-SSM uses the same neighbor discovery mechanism as IPv6 PIM-SM. For more
information, see "
."
DR election
IPv6 PIM-SSM uses the same DR election mechanism as IPv6 PIM-SM. For more information, see
"
."
SPT building
The decision to build an RPT for IPv6 PIM-SM or an SPT for IPv6 PIM-SSM depends on whether the
IPv6 multicast group that the receiver host joins is in the IPv6 SSM group range. The IPv6 SSM
group range reserved by IANA is FF3x::/32, where "x" represents any legal address scope.
Group ID (112 bits)
0xFF
Flags
Scope
0
7
11
15
31