H3C Technologies H3C SecPath F1000-E - Manual (Page 151)

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Solution
Step1 Check the minimum TTL value for multicast forwarding. Use the display current-configuration
command to check the minimum TTL value for multicast forwarding. Increase the TTL value or remove the
multicast minimum-ttl command configured on the interface.
Step2 Check the multicast forwarding boundary configuration. Use the display current-configuration
command to check the multicast forwarding boundary settings. Use the multicast boundary
command to change the multicast forwarding boundary settings.
Step3 Check the multicast filter configuration. Use the display current-configuration command to check
the multicast filter configuration. Change the ACL rule defined in the source-policy command so that
the source/group address of the multicast data can pass ACL filtering.
RPs Unable to Join SPT in PIM-SM
Symptom
An RPT cannot be established correctly, or the RPs cannot join the SPT to the multicast source.
Analysis
• As the core of a PIM-SM domain, the RPs serve specific multicast groups. Multiple RPs can coexist
in a network. Make sure that the RP information on all routers is exactly the same, and a specific
group is mapped to the same RP. Otherwise, multicast forwarding will fail.
• If the static RP mechanism is used, the same static RP command must be executed on all the routers
in the entire network. Otherwise, multicast forwarding will fail.
Solution
Step1 Check that a route is available to the RP. Carry out the display ip routing-table command to check
whether a route is available on each router to the RP.
Step2 Check the dynamic RP information. Use the display pim rp-info command to check whether the RP
information is consistent on all routers.
Step3 Check the configuration of static RPs. Use the display pim rp-info command to check whether the
same static RP address has been configured on all the routers in the entire network.
RPT Establishment Failure or Source Registration Failure in
PIM-SM
Symptom
C-RPs cannot unicast advertise messages to the BSR. The BSR does not advertise bootstrap messages
containing C-RP information and has no unicast route to any C-RP. An RPT cannot be established correctly,
or the DR cannot perform source register with the RP.
Analysis
• The C-RPs periodically send C-RP-Adv messages to the BSR by unicast. If a C-RP has no unicast route
to the BSR, the BSR cannot receive C-RP-Adv messages from that C-RP and the bootstrap message
of the BSR will not contain the information of that C-RP.
• In addition, if the BSR does not have a unicast router to a C-RP, it will discard the C-RP-Adv messages
from that C-RP, and therefore the bootstrap messages of the BSR will not contain the information of
that C-RP.