Switch User Manual

Configuring IGMP at Layer 2
13-2 IGMP Configuration
About Multicasting
Multicastingisusedtosupportreal‐timeapplicationssuchasvideoconferencesorstreaming
audio.Amulticastserverdoesnothavetoestablishaseparateconnectionwitheachclient.It
merelybroadcastsitsservicetothenetwork,andanyhoststhatwanttoreceivethemulticast
registerwiththeirlocalmulticast
switch/router.Althoughthisapproachreducesthenetwork
overheadrequiredbyamulticastserver,thebroadcasttrafficmustbecarefullyprunedatevery
multicastswitch/routeritpassesthroughtoensurethattrafficisonlypassedtothehoststhat
subscribedtothisservice.
TheSecureStackC3switchdeviceusesIGMP(InternetGroup
ManagementProtocol)toqueryfor
anyattachedhostswhowanttoreceiveaspecificmulticastservice.ThedevicelooksuptheIP
MulticastGroupusedforthisserviceandaddsittotheegresslistoftheLevel3interface.Itthen
propagatestheservicerequestontoanyneighboring
multicastswitch/routertoensurethatitwill
continuetoreceivethemulticastservice.
Configuring IGMP at Layer 2
Purpose
ToconfigureIGMPsnoopingfromtheswitchCLI.
Commands
Note: An Enterasys Networks Feature Guide document containing an in-depth discussion of
multicast configuration is located on the Enterasys Networks web site:
http://www.enterasys.com/support/manuals/
For information about... Refer to page...
show igmpsnooping 13-3
set igmpsnooping adminmode 13-3
set igmpsnooping interfacemode 13-4
set igmpsnooping groupmembershipinterval 13-4
set igmpsnooping maxresponse 13-5
set igmpsnooping mcrtrexpiretime 13-6
set igmpsnooping add-static 13-6
set igmpsnooping remove-static 13-7
show igmpsnooping static 13-8
show igmpsnooping mfdb 13-8
clear igmpsnooping 13-9