Introduction 21VLAN 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 andpacket contents. Packets sharing common attributes can be grouped in the same VLAN.For more information, see "Configuring VLANs."Port Based Virtual LANs (VLANs)Port-based VLANs classify incoming packets to VLANs based on their ingress port.For more information, see "Defining VLAN Ports Settings."Full 802.1Q VLAN Tagging ComplianceIEEE 802.1Q defines an architecture for virtual bridged LANs, the services provided in VLANs, and theprotocols and algorithms involved in the provision of these services.GVRP SupportGARP VLAN Registration Protocol (GVRP) provides IEEE 802.1Q-compliant VLAN pruning anddynamic VLAN creation on 802.1Q trunk ports. When GVRP is enabled, the device registers andpropagates VLAN membership on all ports that are part of the active underlying "Spanning TreeProtocol Features" on page 21 topology.For more information, see "Configuring GVRP Parameters."Private VLAN EdgePorts can be assigned to Private VLAN Edge (PVE) groups. A port defined as PVE is protected by anuplink, so that it is isolated from other ports within the same VLAN. The uplink must be a GE port.For more information on Private VLANs, see "Configuring Ports" on page 297.Spanning Tree Protocol FeaturesSpanning Tree Protocol (STP)802.1d Spanning tree is a standard Layer 2 switch requirement that allows bridges to automaticallyprevent and resolve L2 forwarding loops. Switches exchange configuration messages using specificallyformatted frames and selectively enable and disable forwarding on ports.For more information, see "Configuring the Spanning Tree Protocol."
