MLD snooping querier configuration example

As shown in Figure 46:

• The network is a Layer 2-only network.

• Source 1 and Source 2 send IPv6 multicast data to IPv6 multicast groups FF1E::101 and FF1E::102, respectively.

• Host A and Host C are receivers of IPv6 multicast group FF1E::101, and Host B and Host D are receivers of IPv6 multicast group FF1E::102.

• All receiver hosts run MLDv1 and all switches run MLDv1 snooping. Switch A (which is close to the multicast sources) acts as the MLD snooping querier.

To prevent the switches from flooding unknown IPv6 packets in the VLAN, enable all switches to drop unknown IPv6 multicast data packets.

1. Configure Switch A:

   # Enable MLD snooping globally.

   <SwitchA> system-view
   [SwitchA] mld-snooping
   [SwitchA-mld-snooping] quit
   

   # Create VLAN 100, and assign FortyGigE 1/0/1 through FortyGigE 1/0/3 to the VLAN.

   [SwitchA] vlan 100
   [SwitchA-vlan100] port fortygige 1/0/1 to fortygige 1/0/3
   

   # Enable MLD snooping, and enable dropping unknown IPv6 multicast data packets for VLAN 100.

   [SwitchA-vlan100] mld-snooping enable
   [SwitchA-vlan100] mld-snooping drop-unknown
   

   # Enable the MLD snooping querier in VLAN 100.

   [SwitchA-vlan100] mld-snooping querier
   [SwitchA-vlan100] quit
   

2. Configure Switch B:

   # Enable MLD snooping globally.

   <SwitchB> system-view
   [SwitchB] mld-snooping
   [SwitchB-mld-snooping] quit
   

   # Create VLAN 100, and assign FortyGigE 1/0/1 through FortyGigE 1/0/4 to the VLAN.

   [SwitchB] vlan 100
   [SwitchB-vlan100] port fortygige 1/0/1 to fortygige 1/0/4
   

   # Enable MLD snooping, and enable dropping unknown IPv6 multicast data packets for VLAN 100.

   [SwitchB-vlan100] mld-snooping enable
   [SwitchB-vlan100] mld-snooping drop-unknown
   [SwitchB-vlan100] quit
   

3. Configure Switch C:

   # Enable MLD snooping globally.

   <SwitchC> system-view
   [SwitchC] mld-snooping
   [SwitchC-mld-snooping] quit
   

   # Create VLAN 100, and assign FortyGigE 1/0/1 through FortyGigE 1/0/3 to the VLAN.

   [SwitchC] vlan 100
   [SwitchC-vlan100] port fortygige 1/0/1 to fortygige 1/0/3
   

   # Enable MLD snooping, and enable dropping unknown IPv6 multicast data packets for VLAN 100.

   [SwitchC-vlan100] mld-snooping enable
   [SwitchC-vlan100] mld-snooping drop-unknown
   [SwitchC-vlan100] quit
   

4. Configure Switch D:

   # Enable MLD snooping globally.

   <SwitchD> system-view
   [SwitchD] mld-snooping
   [SwitchD-mld-snooping] quit
   

   # Create VLAN 100, and assign FortyGigE 1/0/1 and FortyGigE 1/0/2 to the VLAN.

   [SwitchD] vlan 100
   [SwitchD-vlan100] port fortygige 1/0/1 to fortygige 1/0/2
   

   # Enable MLD snooping, and enable dropping unknown IPv6 multicast data packets for VLAN 100.

   [SwitchD-vlan100] mld-snooping enable
   [SwitchD-vlan100] mld-snooping drop-unknown
   [SwitchD-vlan100] quit
   

# Display statistics for MLD messages learned through MLD snooping on Switch B.

[SwitchB] display mld-snooping statistics
Received MLD general queries:  3
Received MLDv1 specific queries:  0
Received MLDv1 reports:  12
Received MLD dones:  0
Sent     MLDv1 specific queries:  0
Received MLDv2 reports:  0
Received MLDv2 reports with right and wrong records:  0
Received MLDv2 specific queries:  0
Received MLDv2 specific sg queries:  0
Sent     MLDv2 specific queries:  0
Sent     MLDv2 specific sg queries:  0 
Received IPv6 PIM hello:  0
Received error MLD messages:  0

The output shows that all switches except Switch A can receive the MLD general queries after Switch A acts as the MLD snooping querier.