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When C-BSRs connect to other PIM routers through tunnels, static multicast routes must be
configured to make sure the next hop to a C-BSR is a tunnel interface. Otherwise, RPF check is
affected. For more information about static multicast routes, see "Configuring multicast routing
and forwarding."
To configure a C-BSR:
1. Enter system view.
system-view
N/A
2. Enter PIM view.
pim
[
vpn-instance
vpn-instance-name ]
N/A
3. Configure a C-BSR.
c-bsr
ip-address [
scope
group-address { mask-length |
mask } ] [
hash-length
hash-length |
priority
priority ] *
By default, no C-BSRs exist.
4. (Optional.) Configure a BSR
policy.
bsr-policy
ipv4-acl-number
By default, no BSR policies exist,
and all bootstrap messages are
regarded legal.
Configuring a PIM domain border
A PIM domain border determines the transmission boundary of bootstrap messages. Bootstrap
messages cannot cross the domain border in either direction. A number of PIM domain border
interfaces partition a network into different PIM-SM domains.
To configure a PIM domain border:
1. Enter system view.
system-view
N/A
2. Enter interface view.
interface
interface-type
interface-number
N/A
3. Configure a
border.
pim bsr-boundary
By default,
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 range. The loss of one BSMF only affects the RP-set
information of the group ranges that the fragment contains.
If the PIM-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:
1. Enter system view.
system-view
N/A
2. Enter PIM view.
pim
[
vpn-instance
vpn-instance-name ]
N/A
3. D
fragmentation.
undo bsm-fragment
enable
By default, BSM semantic
fragmentation is enabled.