TP-Link TL-SG5426 User Guide - Page 154

3 Spanning Tree Algorithm Configuration Displaying Interface Settings The STA Port Information and STA Trunk Information pages display the current status of ports and trunks in the Spanning Tree. Field Attributes • Spanning Tree - Shows if STA has been enabled on this interface. • STA Status - Displays current state of this port within the Spanning Tree: • Discarding - Port receives STA configuration messages, but does not forward packets. • Learning - Port has transmitted configuration messages for an interval set by the Forward Delay parameter without receiving contradictory information. Port address table is cleared, and the port begins learning addresses. • Forwarding - Port forwards packets, and continues learning addresses. The rules defining port status are: - A port on a network segment with no other STA compliant bridging device is always forwarding. - If two ports of a switch are connected to the same segment and there is no other STA device attached to this segment, the port with the smaller ID forwards packets and the other is discarding. - All ports are discarding when the switch is booted, then some of them change state to learning, and then to forwarding. • Forward Transitions - The number of times this port has transitioned from the Learning state to the Forwarding state. • Designated Cost - The cost for a packet to travel from this port to the root in the current Spanning Tree configuration. The slower the media, the higher the cost. • Designated Bridge - The bridge priority and MAC address of the device through which this port must communicate to reach the root of the Spanning Tree. • Designated Port - The port priority and number of the port on the designated bridging device through which this switch must communicate with the root of the Spanning Tree. • Oper Link Type - The operational point-to-point status of the LAN segment attached to this interface. This parameter is determined by manual configuration or by auto-detection, as described for Admin Link Type in STA Port Configuration on 3-114. • Oper Edge Port - This parameter is initialized to the setting for Admin Edge Port in STA Port Configuration on 3-114 (i.e., true or false), but will be set to false if a BPDU is received, indicating that another bridge is attached to this port. • Port Role - Roles are assigned according to whether the port is part of the active topology connecting the bridge to the root bridge (i.e., root port), connecting a LAN through the bridge to the root bridge (i.e., designated port), or is an alternate or backup port that may provide connectivity if other bridges, bridge ports, or LANs fail or are removed. The role is set to disabled (i.e., disabled port) if a port has no role within the spanning tree. 3-111