Dell POWEREDGE M1000E - Manual (Page 450)

450 IGMP Snooping Commands
User Guidelines
The mcrexpiretime should be less than the group membership interval.
Example
The following example sets the multicast router present expiration time on
VLAN 2 to 60 seconds.
console(config-vlan)#ip igmp mcrtexpiretime 2 60
2CSPC4.XModular-SWUM200.book Page 450 Thursday, March 10, 2011 11:18 AM