70 Switch FeaturesCisco Protocol FilteringThe Cisco Protocol Filtering feature (also known as Link Local ProtocolFiltering) filters Cisco protocols that should not normally be relayed by abridge. The group addresses of these Cisco protocols do not fall within theIEEE defined range of the 802.1D MAC Bridge Filtered MAC GroupAddresses (01-80-C2-00-00-00 to 01-80-C2-00-00-0F).For information about configuring LLPF, settings see "Configuring Port-Based Traffic Control" on page 665.DHCP Layer 2 RelayThis feature permits Layer 3 Relay agent functionality in Layer 2 switchednetworks. The switch supports L2 DHCP relay configuration on individualports, link aggregation groups (LAGs) and VLANs.For information about configuring L2 DHCP Relay settings see "ConfiguringL2 and L3 Relay Features" on page 907.Virtual Local Area Network Supported FeaturesFor information about configuring VLAN features see "Configuring VLANs"on page 539.VLAN SupportVLANs are collections of switching ports that comprise a single broadcastdomain. Packets are classified as belonging to a VLAN based on either theVLAN tag or a combination of the ingress port and packet contents. Packetssharing common attributes can be groups in the same VLAN. ThePowerConnect 8000-series and 8100-series switches are in full compliancewith IEEE 802.1Q VLAN tagging.Port-Based VLANsPort-based VLANs classify incoming packets to VLANs based on their ingressport. When a port uses 802.1X port authentication, packets can be assignedto a VLAN based on the result of the 802.1X authentication a client useswhen it accesses the switch. This feature is useful for assigning traffic toGuest VLANs or Voice VLANs.
