Defining Spanning Tree Interface Settings

The STP Interface Settings page enables you to configure STP on a per-port basis, and to view the information learned by the protocol, such as the designated bridge.

The configuration entered on this page is active for all flavors of the STP protocol.

To configure STP on an interface:

  1. Click Spanning Tree > STP Interface Settings. The STP Interface Settings page displays.
  2. Select an interface and click Edit. The Edit Interface Settings page displays.
  3. Enter the parameters
    • Interface--Select the port number or LAG on which Spanning Tree is configured.
    • STP--Enables or disables STP on the port.
    • Edge Port--Enables or disables Fast Link on the port. If Fast Link mode is enabled for a port, the port state is automatically placed in the Forwarding state when the port link is up. Fast Link optimizes the STP protocol convergence. The options are:
      • Enable--Enables Fast Link immediately.
      • Auto--Enables Fast Link a few seconds after the interface becomes active. This allows STP to resolve loops before enabling Fast Link.
      • Disable--Disables Fast Link.
    • BPDU Handling--Select how BPDU packets are managed when STP is disabled on the port or the switch. BPDUs are used to transmit spanning tree information.
      • Use Global Settings--Select to use the settings defined in the STP Status and Global Settings page.
      • Filtering--Filters BPDU packets when Spanning Tree is disabled on an interface.
      • Flooding--Floods BPDU packets when Spanning Tree is disabled on an interface.
    • Path Cost--Set the port contribution to the root path cost or use the default cost generated by the system.
    • Priority--Set the priority value of the port. The priority value influences the port choice when a bridge has two ports connected in a loop. The priority is a value from 0 to 240, set in increments of 16.
    • Port State--Displays the current STP state of a port.
      • Disabled--STP is currently disabled on the port. The port forwards traffic while learning MAC addresses.
      • Blocking--The port is currently blocked, and cannot forward traffic (with the exception of BPDU data) or learn MAC addresses.
      • Listening--The port is in Listening mode. The port cannot forward traffic, and cannot learn MAC addresses.
      • Learning--The port is in Learning mode. The port cannot forward traffic, but it can learn new MAC addresses.
      • Forwarding--The port is in Forwarding mode. The port can forward traffic and learn new MAC addresses.
    • Designated Bridge ID--Displays the bridge priority and the MAC address of the designated bridge.
    • Designated Port ID--Displays the priority and interface of the selected port.
    • Designated Cost--Displays the cost of the port participating in the STP topology. Ports with a lower cost are less likely to be blocked if STP detects loops.
    • Forward Transitions--Displays the number of times the port has changed from the Blocking state to Forwarding state.
    • Speed--Displays the speed of the port.
    • LAG--Displays the LAG to which the port belongs. If a port is a member of a LAG, the LAG settings override the port settings.
  4. Click Apply. The interface settings are modified, and the Running Configuration file is updated..