3Com 3CBLSG24 User Guide - Page 128

128 CHAPTER 11: CONFIGURING SPANNING TREE ■ Root Guard - Restricts the interface from acting as the root port of the switch. The possible field values are: ■ Enable - Indicates Root Guard is enabled on the port ■ Disable - Indicates Root Guard is disabled on the port. ■ Port State - Displays the current STP state of a port. If enabled, the port state determines what action is taken on traffic. Possible port states are: ■ Disable - Indicates that STP is currently disabled on the port. The port forwards traffic while learning MAC addresses. ■ Blocking - Indicates that the port is currently blocked and cannot forward traffic or learn MAC addresses. Blocking is displayed when Classic STP is enabled. ■ Listening - Indicates that the port is in Listening mode. The port cannot forward traffic nor can it learn MAC addresses. ■ Learning - Indicates that the port is in Learning mode. The port cannot forward traffic, however it can learn new MAC addresses. ■ Forwarding - Indicates that the port is in Forwarding mode. The port can forward traffic and learn new MAC addresses. ■ Discarding - Indicates that the port is in Discarding mode. The port is listening to BPDUs, and discards any other frames it receives. ■ Port Role - Displays the port role assigned by the STP algorithm to provide to STP paths. The possible field values are: ■ Root - Provides the lowest cost path to forward packets to the root switch. ■ Designated - The port or LAG through which the designated switch is attached to the LAN. ■ Alternate - Provides an alternate path to the root switch from the root interface. ■ Backup - Provides a backup path to the designated port path toward the Spanning Tree leaves. Backup ports occur only when two ports are connected in a loop by a Point-to-Point link, or when a LAN has two or more connections connected to a shared segment. ■ Disabled - The port is not participating in the Spanning Tree. ■ Speed - Indicates the speed at which the port is operating.