142
Step
Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter interface view.
interface interface-type
interface-number
N/A
3.
Configure a PIM domain
border.
pim bsr-boundary
By default, an interface is not a
PIM domain border.
Disabling BSM semantic fragmentation
BSM semantic fragmentation enables a BSR to split a BSM into multiple BSM fragments (BSMFs) if
the BSM exceeds the MTU. In this way, a non-BSR router can update the RP-set information for a
group range after receiving all BSMFs for the group range. The loss of one BSMF only affects the
RP-set information of the group ranges that the fragment contains.
If the BIDIR-SM domain contains a device that does not support this feature, you must disable this
feature on all C-BSRs. If you do not disable this feature, such a device regards a BSMF as a BSM
and updates the RP-set information each time it receives a BSMF. It learns only part of the RP-set
information, which further affects the RP election.
To disable BSM semantic fragmentation:
Step
Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter PIM view.
pim
[
vpn-instance
vpn-instance-name
]
N/A
3.
Disable BSM semantic
fragmentation.
undo bsm-fragment
enable
By default, BSM semantic
fragmentation is enabled.
NOTE:
Generally, a BSR performs BSM semantic fragmentation according to the MTU of its BSR interface.
For BSMs originated due to learning of a new PIM neighbor, semantic fragmentation is performed
according to the MTU of the interface that sends the BSMs.
Disabling the device from forwarding BSMs out of their incoming interfaces
By default, the device forwards BSMs out of their incoming interfaces to avoid the situation that some
devices cannot receive the BSMs because of inconsistent routing information. This results in
duplicated traffic. To reduce duplicated traffic, you can disable the device from forwarding BSMs out
of their incoming interfaces if all the devices have consistent routing information.
To disable the device from forwarding BSMs out of their incoming interfaces:
Step
Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter PIM view.
pim
[
vpn-instance
vpn-instance-name
]
N/A
3.
Disable the device from
forwarding BSMs out of
their incoming interfaces.
undo bsm-reflection
enable
By default, the device forwards
BSMs out of their incoming
interfaces.