HP VPN Firewall Appliances Appendix Protocol Reference

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IPv6 administrative scoping overview
Typically, an IPv6 PIM-SM domain contains only one BSR, which is responsible for advertising RP-set
information within the entire IPv6 PIM-SM domain. The information for all multicast groups is forwarded
within the network scope administered by the BSR. This is called the "IPv6 non-scoped BSR mechanism."
To implement refined management, an IPv6 PIM-SM can be divided into one IPv6 global-scoped zone
and multiple IPv6 administratively scoped zones (IPv6 admin-scoped zones). This is called the "IPv6
administrative scoping mechanism."
The IPv6 administrative scoping mechanism effectively releases stress on the management in a
single-BSR domain and enables provision of zone-specific services using private group addresses.
IPv6 admin-scoped zones correspond to IPv6 multicast groups with different scope values in their group
addresses. The boundary of the IPv6 admin-scoped zone is formed by zone border routers (ZBRs). Each
IPv6 admin-scoped zone maintains one BSR, which serves multicast groups within a specific scope. IPv6
multicast protocol packets, such as assert messages and bootstrap messages, for a specific group range
cannot cross the IPv6 admin-scoped zone boundary. IPv6 multicast group ranges served by different IPv6
admin-scoped zones can overlap. An IPv6 multicast group is valid only within its local IPv6
admin-scoped zone, functioning as a private group address.
The IPv6 global-scoped zone maintains a BSR, which serves the IPv6 multicast groups with the Scope
field in their group addresses being 14.
Relationship between IPv6 admin-scoped zones and the IPv6 global-scoped zone
The IPv6 global-scoped zone and each IPv6 admin-scoped zone have their own C-RPs and BSRs. These
devices are effective only to 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-scoped 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-scoped zone and cannot cross the boundary of the zone.