113
Multicast group ranges that are associated with different admin-scoped zones can have
intersections. However, the multicast groups in an admin-scoped zone are valid only within the local
zone, and theses multicast groups are regarded as private group addresses.
The global-scoped zone maintains a BSR for the multicast groups that do not belong to any
admin-scoped zones.
Relationship between admin-scoped zones and the global-scoped zone
The global-scoped zone and each admin-scoped zone have their own C-RPs and BSRs. These
devices are effective only on their respective zones, and the BSR election and the RP election are
implemented independently. Each admin-scoped zone has its own boundary. The multicast
information within a zone cannot cross this boundary in either direction. You can have a better
understanding of the global-scoped zone and admin-scoped zones based on geographical locations
and multicast group address ranges.
•
In view of geographical locations:
An admin-scoped zone is a logical zone for particular multicast groups. The multicast packets
for such multicast groups are confined within the local admin-scoped zone and cannot cross the
boundary of the zone.
Figure 48 Relationship in view of geographical locations
As shown in
, for the multicast groups in a specific group address range, the
admin-scoped zones must be geographically separated and isolated. A router cannot belong to
multiple admin-scoped zones. An admin-scoped zone cannot contain a router that belongs to
any other admin-scoped zone. However, the global-scoped zone includes all routers in the
PIM-SM domain or BIDIR-PIM domain. Multicast packets that do not belong to any
admin-scoped zones are forwarded in the entire PIM-SM domain or BIDIR-PIM domain.
•
In view of multicast group address ranges:
Each admin-scoped zone is designated to specific multicast groups, of which the multicast
group addresses are valid only within the local zone. The multicast groups of different
admin-scoped zones might have intersections. All the multicast groups other than those of the
admin-scoped zones use the global-scoped zone.
Admin-scope 1
Admin-scope 2
Admin-scope 3
Global-scope
C-RP
C-RP
C-RP
C-RP
C-RP
BSR
BSR
BSR
BSR