H3C Technologies H3C S7500E Series Switches - Manual (Page 199)

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enabled on the RPF interface and on the corresponding interface of the RPF neighbor
router, the establishment of a multicast distribution tree will surely fail, causing abnormal
multicast forwarding.
z The same PIM mode must run on the entire network. Otherwise, the establishment of a
multicast distribution tree will surely 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
z If a multicast forwarding boundary has been configured through the multicast boundary
command, any multicast packet will be kept from crossing the boundary, and therefore no
routing entry can be created in the PIM routing table.
z In addition, the source-policy command is used to filter 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