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Enabling and disabling STP

To enable and disable STP:

  1. From the Device Manager menu bar, choose VLAN > STP.
    2. The STP dialog box opens with the Globals tab displayed.

The table that follows explains the fields in the STP Globals tab.


Field Description
StpState
Indicates whether STP is enabled or disabled.
StpForwardBPDU
Indicates whether STP BPDU forwarding is enabled or disabled.
Protocol Type
Specifies the protocol type (i.e., 1eee802.1D).
Priority
Sets the STP bridge priority, in decimal. The range is 0 (highest priority) to 65535 (lowest priority). The default is 32768.
Last Topology Change
The time (in hours:minutes:seconds) since the last topology change was detected.
Total Topology Changes
The total number of topology changes detected since the management entity was last reset or initialized.
Root Identifier
The bridge identifier of the spanning tree root determined by STP that is executed by this node.
Root Cost
The cost of the path to the root as seen from this bridge.
Root Port
The number of the port which offers the lowest cost path from this bridge to the root bridge.
Maximum Age
The maximum age of the STP information learned from the network on any port before it is discarded, in units of hundredths of a second.
Hello Interval
The amount of time between the transmission of configuration bridge PDUs by this node on any port when it is the root of the spanning tree or is trying to become so, in units of hundredths of a second.
Hold Interval
This value determines the interval during which no more than two configuration bridge PDUs are transmitted by this node, in units of hundredths of a second.
Forwarding Delay
This interval, measured in units of hundredths of a second, controls how fast a port changes its spanning state when moving towards the forwarding state.
Bridge Maximum Age
The value in hundredths of a second that all bridges use for MaxAge when this bridge is acting as the root. Note: The 802.1D-1990 standard specifies that the range for this parameter is related to the value of the Bridge Hello Interval. The default is 2000 (20 seconds).
Bridge Hello Interval
The value in hundredths of a second that all bridges use for HelloTime when this bridge is acting as the root. The granularity of this timer is specified by the IEEE 802.1D-1990 standard to be in increments of 1/100 of a second. The default is 200 (2 seconds).
Bridge Forwarding Delay
The value in hundredths of a second that all bridges use for forward delay when this bridge is acting as the root. The default is 1500 (15 seconds).

  1. Set the StpState to enabled or disabled.
    2. Note that the Globals tab allows you to control the StpState for the entire switch. This is the first level of control. The second level occurs at the STP ports level and it allows you to control the StpState for each port. Thus, you need to enable or disable the StpState for the switch and also enable or disable the port status in the Port > STP tab as explained in Step 3.
  2. To enable or disable the port status:
    1. Select a port and choose Edit > Port > STP.
      2. The STP dialog box opens.
    2. Click the Status box to enable or disable STP and then click Apply. Note that the STP for each port is automatically generated.
  3. Enter an STP bridge priority, a Bridge Maximum Age, a Bridge Hello Interval, and a Bridge Forwarding Delay, or just accept the default values.

See also:

Displaying STP port data

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