H3C Technologies H3C S12500-X Series Switches - Manual (Page 198)

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is not on the SPT path, does not have IPv6 multicast routing entries. You can use the display ipv6 pim
routing-table command to display IPv6 PIM routing table information on each switch. For example:
# Display IPv6 PIM multicast routing table information on Switch A.
[SwitchA] display ipv6 pim routing-table
Total 0 (*, G) entry; 1 (S, G) entry
(4001::100, FF3E::101)
Protocol: pim-ssm, Flag:
UpTime: 00:00:11
Upstream interface: Vlan-interface101
Upstream neighbor: 1002::2
RPF prime neighbor: 1002::2
Downstream interface(s) information:
Total number of downstreams: 1
1: Vlan-interface100
Protocol: mld, UpTime: 00:00:11, Expires: 00:03:25
# Display IPv6 PIM multicast routing table information on Switch B.
[SwitchD] display ipv6 pim 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
Protocol: pim-ssm, UpTime: 00:08:02, Expires: 00:03:25
Troubleshooting IPv6 PIM
A multicast distribution tree cannot be correctly built
Symptom
An IPv6 multicast distribution tree cannot be correctly built because no IPv6 multicast forwarding entries
are established on the routers (including routers directly connected with multicast sources or receivers) in
an IPv6 PIM network.
Analysis
• On an IPv6 PIM-DM enabled network, IPv6 multicast data is flooded from the router that directly
connects to the IPv6 multicast source to the routers that directly connects to the receivers. When the
IPv6 multicast data is flooded to a router, the router creates an (S, G) entry only if it has a route to
the IPv6 multicast source. If the router does not have a route to the IPv6 multicast source, or if IPv6
PIM-DM is not enabled on the RPF interface toward the IPv6 multicast source, the router cannot
create an (S, G) entry.