Configuring Administrative Scoping - HP A6600 Configuration Manual

Disabling BSM semantic fragmentation
Generally, a BSR periodically distributes the RP-set information in bootstrap messages within the
BIDIR-PIM 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
bootstrap message fragments (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.
The function of BSM semantic fragmentation is enabled by default. Devices not supporting this function
might deem a fragment as an entire message, thus learning only part of the RP-set information. Therefore,
if such devices exist in the BIDIR-PIM domain, you need to disable the semantic fragmentation function on
the C-BSRs.
To do...
1. Enter system view.
2. Enter public network PIM
view or VPN instance PIM
view.
3. Disable the BSM semantic
fragmentation function.
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.

Configuring administrative scoping

With administrative scoping disabled, a BIDIR-PIM domain has only one BSR. The BSR manages the
whole network. To manage your network more effectively and specifically, partition the BIDIR-PIM domain
into multiple admin-scope zones. Each admin-scope zone maintains a BSR, which serves a specific
multicast group range. The global scope zone also maintains a BSR, which serves all the rest multicast
groups.
Enabling administrative scoping
Before you configure an admin-scope zone, you must enable administrative scoping first.
Perform the following configuration on routers that you want to configure as a C-BSR and ZBR.
To do...
1. Enter system view.
2. Enter public network PIM view
or VPN instance PIM view.
Use the command...
system-view
pim [ vpn-instance
vpn-instance-name ]
undo bsm-fragment enable
Use the command...
system-view
pim [ vpn-instance
vpn-instance-name ]
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Remarks
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Required.
By default, the BSM semantic
fragmentation function is enabled.
Remarks
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