305The output shows that GigabitEthernet 1/0/3 on Switch B has joined FF1E::101 but not FF1E::102.Assume that Source 2 starts sending multicast traffic to FF1E::101. Use the display multicast ipv6forwarding-table to display the IPv6 multicast forwarding table information.# Display the information about FF1E::101 in the IPv6 multicast forwarding table on Switch A.[SwitchA] display multicast ipv6 forwarding-table ff1e::101IPv6 Multicast Forwarding TableTotal 1 entryTotal 1 entry matched00001. (1::1, FF1E::101)MID: 0, Flags: 0x0:0Uptime: 00:08:32, Timeout in: 00:03:26Incoming interface: Vlan-interface101List of 1 outgoing interfaces:1: Vlan-interface104Matched 19648 packets(20512512 bytes), Wrong If 0 packetsForwarded 19648 packets(20512512 bytes)The output shows that Switch A maintains a multicast forwarding entry for multicast packets from Source1 to FF1E::101. No forwarding entry exists for packets from Source 2 to FF1E::101, which indicates thatIPv6 multicast packets from Source 2 are blocked.Troubleshooting MLD snoopingLayer 2 multicast forwarding cannot functionSymptomLayer 2 multicast forwarding cannot function.AnalysisMLD snooping is not enabled.Solution1. Use the display current-configuration command to display the running status of MLD snooping.2. If MLD snooping is not enabled, use the mld-snooping command to enable MLD snooping globally,and then use mld-snooping enable command to enable MLD snooping in VLAN view.3. If MLD snooping is disabled only for the corresponding VLAN, use the mld-snooping enablecommand in VLAN view to enable MLD snooping in the corresponding VLAN.
