System information

Publication date: Feb., 2012
Revision A1
- 67 -
CLIReferenceGuide
Copyright @ 2012 by Amer Networks
Chapter 20 IGMPCommandsofCLI
IGMP
The function, is used to establish the multicast groups to forward the
multicastpackettothememberports,and,innature,avoidswastingthe
bandwidth whileIPmulticastpacketsarerunningoverthe network.This
isbecauseaswitchthatdoesnotsupportIGMPorIGMPSnoopingcannot
tell the multicast
 packet from the broadcast packet, so it can only treat
themallasthebroadcastpacket.WithoutIGMPS nooping, themulticast
packet forwarding function is plain and nothing is different from
broadcastpack et.
A switch supported IGMP Snooping with the functions of query, report
and leave, a type of packet
exchanged between IP Multicast
Router/Switch and IP Multicast Host, can update the inf ormation of the
Multicast table when a member (port) joins  or leaves an IP Multicast
Destination Address. With this function, once a switch receives an IP
multicastpacket,itwillforwardthepackettothememberswhojoinedin

aspecifiedIPmulticastgroupbefore.
Thepacketswi ll bediscardedbytheIGMPSnoopingiftheusertransmits
multicast packets to the multicast group that had not been built up in
advance.IGMPmodeenablestheswitchtoissueIGMPfunctionthatyou
enableIGMPproxyorsnoopingon
theswitch,whichconnectstoarouter
closertotherootofthetree.Thisinterfaceistheupstreaminterface.The
routerontheupstreaminterfaceshouldberunningIGMP.
Table 19: IGMP Commands
Command Function
compatibility
Set the Versions of IGMP Operating on Hosts and Routers
delete
Delete commands what you set on the switch
fast-leave
Set per-port Fast Leave
filtering
The IP Multicast Group that will be filtered
flooding
Set IGMP Flooding Mode
lmqi
Set per-VLAN Last Member Query Interval
proxy
Set IGMP Proxy Mode
qi
Set per-VLAN Query Interval
qri
Set per-VLAN Query Response Interval
querier
Set per-VLAN IGMP Querier
router
Set Router Port
rv
Set per-VLAN Robustness Variable
show
Show IGMP Snooping Information