444 Dell PowerConnect 55xx Systems User GuideFILE LOCATION: C:\Users\gina\Desktop\Checkout_new\Maintenance Projects\DellContax\sources\CxUGSwitching_STP.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 LY– BPDU Guard — Check to enable BPDU Guard on the port.– Root Guard — Check to prevent devices outside the network corefrom being assigned the spanning tree root.– Port State — Displays the current STP state of a port. If the port stateis not disabled, it determines what forwarding action is taken ontraffic. The possible port states are:• Disabled — STP is currently disabled on the port. The portforwards traffic while learning MAC addresses.• Blocking — The port is currently blocked and cannot be used toforward traffic or learn MAC addresses. Blocking is displayedwhen Classic STP is enabled.• Listening — The port is currently in the listening mode. The portcannot forward traffic nor can it learn MAC addresses.• Learning — The port is currently in the learning mode. The portcannot forward traffic, however it can learn new MAC addresses.• Forwarding — The port is currently in the forwarding mode. Theport can forward traffic and learn new MAC addresses.– Role — Displays the port role assigned by the STP algorithm thatprovides STP paths. The possible options are:• Root — This port provides the lowest cost path to forward packetsto root switch.• Designated — This port is the interface through which the bridgeis connected to the LAN, which provides the lowest cost pathfrom the LAN to the Root Bridge.• Alternate — This port provides an alternate LAG to the rootswitch from the root interface.• Backup — This port provides a backup path to the designatedport. Backup ports occur only when two ports are connected in aloop by a point-to-point link. Backup ports also occur when a LANhas two or more connections connected to a shared segment.• Disabled — This port is not participating in the Spanning Tree.
