560 CHAPTER 42: IGMP SNOOPING CONFIGURATION
■ Keep forwarding entries for version 3 static (*, G) joins;
■ Clear forwarding entries from version 3 static (S, G) joins, which will be 
restored when IGMP Snooping is switched back to version 3.
For details about static joins, Refer to “Configuring Static Ports” on page 561.
Configuring IGMP 
Snooping Port 
Functions
Configuration
Prerequisites
Before configuring IGMP Snooping port functions, complete the following tasks:
■ Enable IGMP Snooping in the VLAN or enable IGMP on the desired VLAN 
interface
■ Configure the corresponding port groups.
Before configuring IGMP Snooping port functions, prepare the following data:
■ Aging time of router ports,
■ Aging timer of member ports, and
■ Multicast group and multicast source addresses
Configuring Aging
Timers for Dynamic
Ports
If the switch receives no IGMP general queries or PIM hello messages on a dynamic 
router port, the switch removes the port from the router port list when the aging 
timer of the port expires.
If the switch receives no IGMP reports for a multicast group on a dynamic member 
port, the switch removes the port from the outgoing port list of the forwarding 
table entry for that multicast group when the aging timer of the port for that 
group expires.
If multicast group memberships change frequently, you can set a relatively small 
value for the member port aging timer, and vice versa.
Configuring aging timers for dynamic ports globally
Follow these steps to configure aging timers for dynamic ports globally:
Configuring aging timers for dynamic ports in a VLAN
Follow these steps to configure aging timers for dynamic ports in a VLAN:
To do…  Use the command…  Remarks 
Enter system view  system-view - 
Enter IGMP Snooping view  igmp-snooping - 
Configure router port aging 
time 
router-aging-time interval Optional
105 seconds by default 
Configure member port aging 
time 
host-aging-time interval Optional
260 seconds by default