F3726, F3211, F3174, R5135, R3816-HP Firewalls and UTM Devices Network Management Configuration Guide-6PW100

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NOTE:
If you configure the BS period or the BS timeout timer, the system uses the configured one instead of the
default one.
1622BDisabling 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:
Ste
p
Command Remarks
801. Enter system view.
system-view
N/A
802. Enter public network PIM view.
pim N/A
803. Disable the BSM semantic
fragmentation function.
undo bsm-fragment enable
By default, the BSM semantic
fragmentation function is enabled.
778BConfiguring 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-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 remaining
multicast groups.
1623BEnabling administrative scoping
Before you configure an admin-scope zone, you must enable administrative scoping.
Perform the following configuration on all routers in the PIM-SM domain.
To enable administrative scoping: