H3C Technologies H3C S7500E Series Switches - Manual (Page 295)

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Solution
1) Use the display acl ipv6 command to check the configured IPv6 ACL rule. Make sure that
the IPv6 ACL rule conforms to the IPv6 multicast group policy to be implemented.
2) Use the display this command in MLD snooping view or the corresponding interface view
to check whether the correct IPv6 multicast group policy has been applied. If not, use the
group-policy or mld-snooping group-policy command to apply the correct IPv6 multicast
group policy.
3) Use the display current-configuration command to check whether the function of
dropping unknown IPv6 multicast data is enabled. If not, use the drop-unknown or
mld-snooping drop-unknown command to enable the function of dropping unknown IPv6
multicast data.
Appendix
Processing of IPv6 Multicast Protocol Messages
With Layer 3 multicast routing enabled, an MLD snooping switch processes IPv6 multicast
protocol messages differently under different conditions, specifically as follows:
1) If only MLD is enabled, or both MLD and IPv6 PIM are enabled on the switch, the switch:
z Maintains dynamic member ports or dynamic router ports according to MLD packets.
z Maintains dynamic router ports according to IPv6 PIM hello packets.
2) In only IPv6 PIM is enabled on the switch:
z The switch broadcasts MLD messages as unknown messages in the VLAN.
z Upon receiving an IPv6 PIM hello message, the switch will maintain the corresponding
dynamic router port.
3) When MLD is disabled on the switch:
z If IPv6 PIM is disabled, the switch deletes all its dynamic member ports and dynamic router
ports.
z If IPv6 PIM is enabled, the switch deletes only its dynamic member ports without deleting
its dynamic router ports.
On a switch with Layer-3 IPv6 multicast routing enabled, use the display mld group port-info
command to view Layer-2 port information.
For more information about the display mld group port-info command, see MLD
Configuration Commands in the IP Multicast Command Reference.
4) When IPv6 PIM is disabled on the switch:
z If MLD is disabled, the switch deletes all its dynamic router ports.
z If MLD is enabled, the switch maintains all its dynamic member ports and dynamic router
ports.