20 Dell PowerConnect 55xx Systems User GuideFILE LOCATION: C:\Users\gina\Desktop\Checkout_new\Maintenance Projects\DellContax\sources\CxUGFeatures.fmD E L L C O N F I D E N T I A L – P R E L I M I N A R Y 1 0 / 3 0 / 1 3 - F O R P R O O F O N LYLayer 2 FeaturesIGMP SnoopingInternet Group Membership Protocol (IGMP) Snooping examines IGMPframe contents, when they are forwarded by the device from work stations toan upstream Multicast router. From the frame, the device identifies workstations configured for Multicast sessions, and which Multicast routers aresending Multicast frames. The IGMP Querier simulates the behavior of aMulticast router. This enables snooping of the Layer 2 Multicast domain evenif there is no Multicast router.For more information, see "IGMP Snooping" on page 528.Port MirroringPort mirroring monitors network traffic by forwarding copies of incoming andoutgoing packets from a monitored port to a monitoring port. Users specifywhich target port receives copies of all traffic passing through a specifiedsource port.For more information, see "Port Mirroring" on page 418.Broadcast Storm ControlStorm Control enables limiting the number of Multicast and Broadcastframes accepted by and forwarded by the device.When Layer 2 frames are forwarded, Broadcast and Multicast frames areflooded to all ports on the relevant VLAN. This occupies bandwidth, andloads all nodes connected on all ports.For more information, see "Storm Control" on page 415.
