NOTE
Saving the results of each troubleshooting step is recommended. If troubleshooting fails to correct the fault,
you will have a record of your actions to provide Huawei technical support personnel.
Procedure
Step 1
Check that the PIM routing table contains correct (*, G) entries.
Run the
display pim routing-table
group-address
command on the device to check whether
the PIM routing table contains correct (*, G) entries. Focus on checking whether the downstream
interface list contains downstream interfaces to forward data to all (*, G) group members.
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If the (*, G) entries exist and are all correct in the PIM routing table, run the
display
multicast forwarding-table
group-address
command every 15 seconds to check whether
the forwarding table contains (S, G) entries associated with the (*, G) entries and whether
the value of the
Matched
field in the command output keeps increasing.
–
If the forwarding table contains associated (S, G) entries and the value of the
Matched
field keeps increasing, it indicates that the upstream device can normally
forward multicast data to the current device but the current device fails to forward the
data downstream, for example, a too small TTL value or a forwarding fault.
–
If the forwarding table does not contain associated (S, G) entries or the value of the
Matched
field remains unchanged, do as follows:
–
If the current device is not an RP, it indicates that the current device has not received
any multicast data. The fault may be caused by the upstream device. Then check
whether the PIM routing table on the upstream device contains correct (S, G) entries.
–
If the current device is already an RP, it indicates the RPT has been set up but the
RP fails to receive the multicast data from the multicast source. The fault may be
caused by a failure in source's DR registration. In such a case, go to Step 10.
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If the PIM routing table does not contain correct (*, G) entries, go to Step 2.
Step 2
Check that the downstream interface has received Join messages.
Run the
display pim control-message counters
interface
interface-type interface-number
message-type join-prune
command to check whether the number of received Join/Prune
messages on the downstream interface keeps increasing.
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If the number of received Join/Prune messages on the downstream interface does not
increase, run the
display pim control-message counters
interface
interface-type
interface-number
message-type join-prune
command on the downstream device to check
whether the downstream device has sent Join/Prune messages upstream.
–
If the command output shows that the number of sent Join/Prune messages keeps
increasing, it indicates that the downstream device has sent Join/Prune messages. The
fault may be caused by a failure in PIM neighbor communication. In such a case, go to
Step 10.
–
If the command output shows that the number of sent Join/Prune messages does not
increase, it indicates the downstream device experiences a fault. Then locate the fault.
l
If the number of received Join/Prune messages on the downstream interface keeps
increasing, go to Step 3.
Step 3
Check that PIM-SM is enabled on interfaces.
The following interfaces are easy to be ignored in enabling PIM-SM:
Huawei AR2200-S Series Enterprise Routers
Troubleshooting
8 Multicast
Issue 01 (2012-01-06)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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