M A G N U M 6 K S W I T C H E S , M N S - 6 K U S E R G U I D Etraffic only goes to the ports requesting the traffic. The Magnum 6K family of switches, usingIGMP-L2, can perform the similar tasks a Layer 3 device performs for IGMP.For a Layer 2 IGMP environment, all Magnum 6K family of switches have to be enabled in theIGMP-L2. This is done using the CLI command 'set igmp mode=l2' which will be describedlater.In a Layer 2 network, without IGMP-L2, there is no querier nor is there any capability for thedevices to use IGMP snooping to join a multicast group. Thus - the traffic picture from amulticast device would look as shown below.R1 R2R3 R4R5R6T1T1T2T2FIGURE 120 - In a Layer 2 network, an IGMP multicast traffic goes to all the nodes. In the figure, T1, asurveillance camera, using multicast, will send the traffic to all the nodes - R1 through R6 - irrespective of whetherthey want to view the surveillance traffic or not. The traffic is compounded when additional cameras are added tothe network. End result is that users R1 through R6 see the network as heavily loaded and simple day to dayoperations may appear sluggish.219
