Configuring Administrative Scoping - HP MSR ASM Configuration Manual

Disabling BSM semantic fragmentation
Generally, a BSR periodically distributes the RP-set information in bootstrap messages within the PIM-SM
domain. It encapsulates a BSM in an IP datagram and might split the datagram into fragments if the
message exceeds the MTU. In respect of such IP fragmentation, loss of a single IP fragment leads to
unavailability of the entire message.
Semantic fragmentation of BSMs can solve this issue. When a BSM exceeds the MTU, it is split to multiple
BSMFs.
After receiving a BSMF that contains the RP-set information of one group range, a non-BSR router
•
updates corresponding RP-set information directly.
• If the RP-set information of one group range is carried in multiple BSMFs, a non-BSR router updates
corresponding RP-set information after receiving all these BSMFs.
Because the RP-set information contained in each segment is different, loss of some IP fragments will not
result in dropping of the entire message.
Generally, a BSR performs BSM semantic fragmentation according to the MTU of its BSR interface.
However, the semantic fragmentation of BSMs originated due to learning of a new PIM neighbor is
performed according to the MTU of the outgoing interface.
The function of BSM semantic fragmentation is enabled by default. A device that does not support this
function might regard a fragment as an entire message and learns only part of the RP-set information.
Therefore, if such devices exist in the PIM-SM domain, you need to disable the semantic fragmentation
function on the C-BSRs.
To disable the BSM semantic fragmentation function:
Step
1. Enter system view.
2. Enter public network PIM
view or VPN instance PIM
view.
3. Disable the BSM semantic
fragmentation function.

Configuring administrative scoping

When administrative scoping is disabled, a PIM-SM domain has only one BSR. The BSR manages the
whole network. To manage your network more effectively and specifically, partition the PIM-SM domain
into multiple admin-scoped zones. Each admin-scoped zone maintains a BSR, which serves a specific
multicast group range. The global-scoped zone also maintains a BSR, which serves all the remaining
multicast groups.
Enabling administrative scoping
Before you configure an admin-scoped zone, you must enable administrative scoping.
Perform the following configuration on all routers in the PIM-SM domain.
To enable administrative scoping:
Step
1. Enter system view.
Command
system-view
pim [ vpn-instance
vpn-instance-name ]
undo bsm-fragment enable
Command
system-view
67
Remarks
N/A
N/A
By default, the BSM semantic
fragmentation function is enabled.
Remarks
N/A