
15-6
Multimedia Traffic Control with IP Multicast (IGMP)     
CLI: Configuring and Displaying IGMP
Multimedia Traffic Control 
with IP Multicast (IGMP)
■Querier Capability: The switch performs this function for IGMP on 
VLANs having an IP address when there is no other device in the VLAN 
acting as querier. See “Querier Operation” on page 15-18.
Notes Whenever IGMP is enabled, the switch generates an Event Log message 
indicating whether querier functionality is enabled.
IP multicast traffic groups are identified by IP addresses in the range of  
224.0.0.0 to 239.255.255.255. Also,  incoming IGMP packets intended for 
reserved, or “well-known” multicast addresses automatically flood through all 
ports (except the port on which the packets entered the switch). For more on 
this topic, see “The Switch Excludes Well-Known or Reserved Multicast 
Addresses from IP Multicast Filtering” on page 15-19.
For more information, refer to “How IGMP Operates” on page 15-11.
CLI: Configuring and Displaying IGMP IGMP Commands Used in This Section
show ip igmp configuration page 15-7
ip igmp page 15-8
high-priority-forward page 15-9
auto <[ethernet] <port-list> page 15-9
blocked <[ethernet] <port-list> page 15-9
forward <[ethernet] <port-list> page 15-9
querier page 15-10
show ip igmp  See “Internet Group Manageme nt Protocol (IGMP) 
Status” on page 17-19