3-2 
 
z  If the multicast MAC address entry to be created already exists, the system gives you a prompt. 
z  If you want to add a port to a multicast MAC address entry created through the mac-address 
multicast command, you need to remove the entry first, create this entry again, and then add the 
specified port to the forwarding ports of this entry.  
z  You cannot enable link aggregation on a port on which you have configured a multicast MAC 
address, and you cannot configure a multicast MAC address on an aggregation port. 
z  You cannot configure a multicast MAC address starting with 01005e in an 
IGMP-Snooping-enabled VLAN. You can do that if IGMP Snooping is not enabled in the VLAN. 
 
Configuring Dropping Unknown Multicast Packets 
Generally, if the multicast address of the multicast packet received on the switch is not registered on the 
local switch, the packet will be flooded in the VLAN. When the function of dropping unknown multicast 
packets is enabled, the switch will drop any multicast packets whose multicast address is not registered. 
Thus, the bandwidth is saved and the processing efficiency of the system is improved.  
Table 3-3 Configure dropping unknown multicast packet 
Operation  Command  Remarks 
Enter system view  system-view — 
Configure dropping unknown 
multicast packets 
unknown-multicast drop 
enable 
Required 
By default, the function of 
dropping unknown multicast 
packets is disabled. 
 
Displaying Common Multicast Configuration 
After the above-described configuration, you can use the display command in any view to verify the 
configuration.  
Table 3-4 Display common multicast configuration 
Operation  Command  Remarks 
Display the created multicast 
MAC table entries 
display mac-address multicast 
[ static { { { mac-address vlan vlan-id 
| vlan vlan-id } [ count ] } | count } ] 
You can execute the 
display commands in 
any view.