414
for a specific group range cannot cross the IPv6 admin-scope zone boundary. IPv6 multicast group
ranges served by different IPv6 admin-scope zones can overlap. An IPv6 multicast group is valid
only within its local IPv6 admin-scope zone, functioning as a private group address.
The IPv6 global scope zone maintains a BSR, which serves the IPv6 multicast groups with the
Scope field in their group addresses being 14.
Relationship between IPv6 admin-scope zones and the IPv6 global scope zone
The IPv6 global scope zone and each IPv6 admin-scope 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 IPv6 admin-scoped zone has its own boundary. The IPv6
multicast information within a zone cannot cross this boundary in either direction. You can have a
better understanding of the IPv6 global-scoped zone and IPv6 admin-scoped zones based on
geographical locations and the scope field values.
•
In view of geographical locations:
An IPv6 admin-scope zone is a logical zone for particular IPv6 multicast groups with the same scope
filed value. The IPv6 multicast packets for such IPv6 multicast groups are confined within the local
IPv6 admin-scope zone and cannot cross the boundary of the zone.
Figure 125 Relationship in view of geographical locations
As shown in
, for the IPv6 multicast groups with the same scope field value, the IPv6
admin-scope zones must be geographically separated and isolated. The IPv6 global-scoped
zone includes all routers in the IPv6 PIM-SM domain or IPv6 BIDIR-PIM domain. IPv6 multicast
packets that do not belong to any IPv6 admin-scope zones are forwarded in the entire IPv6
PIM-SM domain or IPv6 BIDIR-PIM domain.
•
In view of the scope field values:
In terms of the scope field values, the scope field in an IPv6 multicast group address shows
which zone the IPv6 multicast group belongs to.
Figure 126 IPv6 multicast address format
