14 Dell PowerConnect 28xx Systems User Guide• Short-Reach — Reduction of power over Ethernet cables shorter than 40m.IGMP SnoopingInternet Group Membership Protocol (IGMP) Snooping examines IGMP frame contents, when they areforwarded by the device from work stations to an upstream Multicast router. From the frame, the deviceidentifies work stations configured for Multicast sessions, and which Multicast routers are sendingMulticast frames.Port MirroringThe port mirroring mechanism monitors and mirrors network traffic by forwarding copies of incomingand outgoing packets from a monitored port to a monitoring port. Users can specify which target portreceives copies of all traffic passing through one or more source ports.Storm ControlStorm Control enables limiting the amount of Multicast, Broadcast and Unknown Unicast framesaccepted and forwarded by the switch. When Layer 2 frames are forwarded, Broadcast and Multicastframes are flooded to all ports on the relevant VLAN. All nodes connected to these ports accept andattempt to process these frames, thus placing load on both the network links and the host operatingsystem.Dynamic VLAN Assignment (DVA)Dynamic VLAN Assignment allows automatic assignment of users to VLANs during the RADIUS serverauthentication. When a user is authenticated by the RADIUS server, the user is automatically joined tothe VLAN configured on the RADIUS server.VLAN Supported FeaturesVLAN SupportVLANs are collections of switching ports that comprise a single broadcast domain. Packets are classifiedas belonging to a VLAN based on either the VLAN tag or based on a combination of the ingress port andpackage contents. Packets sharing common attributes can be grouped in the same VLAN.Port Based Virtual LANs (VLANs)Port-based VLANs classify incoming packets to VLANs based on their ingress port.Link AggregationThe PowerConnect 28xx switches support up to eight aggregated links. Each of the eight aggregatedlinks may be defined with up to eight member ports to form a single Link Aggregated Group (LAG).The benefits of this facility are:• Fault tolerance protection from physical link disruption
