Troubleshooting Ipv6 Pim Configuration; Failure To Build A Multicast Distribution Tree Correctly - HP 6125G Configuration Manual

# Display IPv6 PIM multicast routing table information on Switch B.
[SwitchD] display pim ipv6 routing-table
Total 0 (*, G) entry; 1 (S, G) entry
(4001::100, FF3E::101)
Protocol: pim-ssm, Flag: LOC
UpTime: 00:08:02
Upstream interface: Vlan-interface300
Upstream neighbor: NULL
RPF prime neighbor: NULL
Downstream interface(s) information:
Total number of downstreams: 1
1: Vlan-interface105

Troubleshooting IPv6 PIM configuration

Failure to build a multicast distribution tree correctly

Symptom
None of the routers in the network (including routers directly connected with IPv6 multicast sources and
receivers) have IPv6 multicast forwarding entries. That is, a multicast distribution tree cannot be built
correctly and clients cannot receive IPv6 multicast data.
Analysis
An IPv6 PIM routing entry is created based on an IPv6 unicast route, whichever IPv6 PIM mode is
•
running. Multicast works only when unicast does.
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 fail, resulting in abnormal multicast forwarding.
IPv6 PIM requires that the same IPv6 PIM mode (namely, DM or SM) must run on the entire network.
•
Otherwise, the establishment of a multicast distribution tree will fail, resulting in abnormal multicast
forwarding.
Solution
Use the display ipv6 routing-table command to verify that a unicast route exists to the IPv6
1.
multicast source or the RP.
Use the display pim ipv6 interface command to verify that the RPF interface is IPv6 PIM enabled.
2.
If IPv6 PIM is not enabled on the interface, use the pim ipv6 dm or pim ipv6 sm command to enable
IPv6 PIM.
Use the display pim ipv6 neighbor command to verify that the RPF neighbor is an IPv6 PIM
3.
neighbor.
Verify that IPv6 PIM and MLD are enabled on the interfaces that are directly connected to the IPv6
4.
multicast source and to the receiver.
Use the display pim ipv6 interface verbose command to verify that the same PIM mode is enabled
5.
on the RPF interface and the corresponding interface of the RPF neighbor router.
Protocol: pim-ssm, UpTime: 00:08:02, Expires: 00:03:25
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