Ssm model implementation in ipv6 pim – H3C Technologies H3C SecPath F1000-E User Manual
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whereas the global scope zone covers all routers in the IPv6 PIM-SM domain. Multicast packets that do
not belong to any admin-scope zones can be transmitted in the entire IPv6 PIM-SM domain.
2.
In terms of multicast group address Scope field
As shown in
, the Scope field in each IPv6 multicast group address indicates the admin-scope
zone the corresponding multicast group belongs to.
Figure 8 IPv6 multicast address format
The admin-scope zone range increases with the value of the Scope field. For example, value E indicates
IPv6 global scope, which contains other admin-scope zones with the Scope field values smaller than E.
Possible values of the Scope field are given in
.
Table 2 Values of the Scope field
Value Meaning
Remarks
0, F
Reserved
—
1 Interface-local
scope
—
2 Link-local
scope
—
3
Subnet-local scope
IPv6 admin-scope zone
4
Admin-local scope
IPv6 admin-scope zone
5
Site-local scope
IPv6 admin-scope zone
6, 7, 9 through D
Unassigned
IPv6 admin-scope zone
8
Organization-local scope
IPv6 admin-scope zone
E
Global scope
IPv6 global-scope zone
SSM Model Implementation in IPv6 PIM
The source-specific multicast (SSM) model and the any-source multicast (ASM) model are two opposite
models. Presently, the ASM model includes the IPv6 PIM-DM and IPv6 PIM-SM modes. The SSM model
can be implemented by leveraging part of the IPv6 PIM-SM technique.
The SSM model provides a solution for source-specific multicast. It maintains the relationships between
hosts and routers through MLDv2. IPv6 PIM-DM implements IPv6 multicast forwarding by building SPTs
rooted at the IPv6 multicast source through the “flood and prune” mechanism. Although an SPT has the
shortest path, it is built in a low efficiency. Therefore the IPv6 PIM-DM mod is not suitable for large- and
medium-sized networks.
In actual application, part of the IPv6 PIM-SM technique is adopted to implement the SSM model. In the
SSM model, receivers know exactly where an IPv6 multicast source is located by means of