H3C Technologies H3C S12500-X Series Switches - Manual (Page 114)

104
Solution
1. Use display current-configuration to verify the multicast forwarding boundary settings. Use
multicast boundary to change the multicast forwarding boundary settings to make the multicast
packet able to cross the boundary.
2. Use display current-configuration to verify the multicast data filter. Change the ACL rule defined in
the source-policy command so that the source/group address of the multicast data can pass ACL
filtering.
An RP cannot join an SPT in PIM-SM
Symptom
An RPT cannot be correctly built, or an RP cannot join the SPT toward the multicast source.
Analysis
• RPs are the core of a PIM-SM domain. An RP provides services for a specific multicast group, and
multiple RPs can coexist on a network. Make sure the RP information on all routers is exactly the
same to map a specific multicast group to the same RP. Otherwise, multicast forwarding fails.
• If a static RP is configured, use the same static RP configuration on all routers on the entire network.
Otherwise, multicast forwarding fails.
Solution
1. Use display ip routing-table to verify that a unicast route to the RP is available on each router.
2. Use display pim rp-info to verify that the dynamic RP information is consistent on all routers.
3. Use display pim rp-info to verify that the same static RPs are configured on all routers on the
network.
An RPT cannot be built or multicast source registration fails in
PIM-SM
Symptom
The C-RPs cannot unicast advertisement messages to the BSR. The BSR does not advertise BSMs
containing C-RP information and has no unicast route to any C-RP. An RPT cannot be correctly established,
or the source-side DR cannot register the multicast source with the RP.
Analysis
• The C-RPs periodically send advertisement messages to the BSR by unicast. If a C-RP has no unicast
route to the BSR, it cannot send advertisement messages to the BSR, and the BSR cannot advertise
BSMs containing the information of the C-RP.
• If the BSR does not have a unicast route to a C-RP, it discards the advertisement messages from the
C-RP. Therefore, the BSR cannot advertise BSMs containing the information of the C-RP.
• RPs are the core of a PIM-SM domain. Make sure the RP information on all routers is exactly the
same to map a specific multicast group to the same RP, and a unicast route to the RP is available on
the routers.