H3C Technologies H3C S12500 Series Switches - Manual (Page 445)

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• IPv6 PIM must be enabled on the RPF interface. An RPF neighbor must be an IPv6 PIM neighbor as
well. If IPv6 PIM is not enabled on the RPF interface or the RPF neighbor, the establishment of a
multicast distribution tree will surely fail, resulting in abnormal multicast forwarding.
• IPv6 PIM requires that the same IPv6 PIM mode (DM or SM) must run on the entire network.
Otherwise, the establishment of a multicast distribution tree will surely fail, resulting in abnormal
multicast forwarding.
Solution
1. Use the display ipv6 routing-table command to verify that a unicast route exists to the IPv6
multicast source or the RP.
2. Use the display pim ipv6 interface command to verify the IPv6 PIM information on each interface.
If IPv6 PIM is not enabled on the interface, use the pim ipv6 dm or pim ipv6 sm command to enable
IPv6 PIM.
3. Use the display pim ipv6 neighbor command to verify that the RPF neighbor is an IPv6 PIM
neighbor.
4. Check that IPv6 PIM and MLD are enabled on the interfaces directly connecting to the IPv6
multicast source and to the receiver.
5. Use the display pim ipv6 interface verbose command to verify that the same IPv6 PIM mode is
enabled on the RPF interface and the corresponding interface of the RPF neighbor router.
6. Use the display current-configuration command to verify the IPv6 PIM mode information on each
interface. Make sure that the same IPv6 PIM mode is enabled on all the routers: IPv6 PIM-SM on all
routers, or IPv6 PIM-DM on all routers.
IPv6 multicast data abnormally terminated on an intermediate
router
Symptom
An intermediate router can receive IPv6 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 IPv6 PIM routing table.
Analysis
• If an IPv6 multicast forwarding boundary has been configured through the multicast ipv6 boundary
command, any IPv6 multicast packet will be kept from crossing the boundary, and therefore no
routing entry can be created in the IPv6 PIM routing table.
• In addition, the source-policy command filters received IPv6 multicast packets. If the IPv6 multicast
data fails to pass the IPv6 ACL rule defined in this command, IPv6 PIM cannot create the route entry,
either.
Solution
1. Use the display current-configuration command to verify the IPv6 multicast forwarding boundary
settings. Use the multicast ipv6 boundary command to change the IPv6 multicast forwarding
boundary settings.
2. Use the display current-configuration command to verify the IPv6 multicast filter configuration.
Change the IPv6 ACL rule defined in the source-policy command so that the source/group address
of the IPv6 multicast data can pass IPv6 ACL filtering.