H3C Technologies H3C S10500 Series Switches - Manual (Page 216)

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the RPF interface and on the corresponding interface of the RPF neighbor router, the establishment
of a multicast distribution tree will fail, causing abnormal multicast forwarding.
• The same PIM mode must run on the entire network. Otherwise, the establishment of a multicast
distribution tree will fail, causing abnormal multicast forwarding.
Solution
1. Check unicast routes. Use the display ip routing-table command to check whether a unicast route
exists from the receiver host to the multicast source.
2. Check that PIM is enabled on the interfaces, especially on the RPF interface. Use the display pim
interface command to view the PIM information on each interface. If PIM is not enabled on the
interface, use the pim dm or pim sm command to enable PIM-DM or PIM-SM.
3. Check that the RPF neighbor is a PIM neighbor. Use the display pim neighbor command to view
the PIM neighbor information.
4. Check that PIM and IGMP are enabled on the interfaces directly connecting to the multicast source
and to the receivers.
5. Check that the same PIM mode is enabled on related interfaces. Use the display pim interface
verbose command to check whether the same PIM mode is enabled on the RPF interface and the
corresponding interface of the RPF neighbor router.
6. Check that the same PIM mode is enabled on all the routers in the entire network. Make sure that
the same PIM mode is enabled on all the routers: PIM-SM on all routers, or PIM-DM on all routers.
In the case of PIM-SM, also check that the BSR and RP configurations are correct.
Multicast data abnormally terminated on an intermediate
router
Symptom
An intermediate router can receive multicast data successfully, but the data cannot reach the last hop
router. An interface on the intermediate router receives data but no corresponding (S, G) entry is created
in the PIM routing table.
Analysis
• If a multicast forwarding boundary has been configured through the multicast boundary command,
any multicast packet will be kept from crossing the boundary, and no routing entry can be created
in the PIM routing table.
• In addition, the source-policy command filters received multicast packets. If the multicast data fails
to pass the ACL rule defined in this command, PIM cannot create the route entry either.
Solution
1. 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.
2. 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.