F3726, F3211, F3174, R5135, R3816-HP Firewalls and UTM Devices Appendix Protocol Reference-6PW100

112

Value Meanin

Remarks

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.

IPv6 PIM-SSM overview

The SSM model and the ASM model are opposites. 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,

and 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 application, MLDv2 and part of 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 using

advertisements, consultancy, and so on. This mode does not required RP or RPT, and does not require a

source registration process for discovering IPv6 multicast sources in other IPv6 PIM domains.

The working mechanism of IPv6 PIM-SSM is summarized as follows:

• Neighbor discovery

• DR election

• SPT building

Neighbor discovery

IPv6 PIM-SSM uses the same neighbor discovery mechanism as in IPv6 PIM-SM. For more information,

see "Neighbor discovery."

DR election

IPv6 PIM-SSM uses the same DR election mechanism as in IPv6 PIM-SM. For more information, see "DR

election."

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 will join falls into the IPv6 SSM group range. The IPv6 SSM group range

that IANA has reserved is FF3x::/32, where x represents any legal address scope.