STP Settings

The STP Settings tab helps you to edit the STP details of the ports.

You can click on Config button and you are redirected to the MSTP page. For more information on this, refer to the MSTP.

STP Path Cost Behavior on Switches Upgraded from Firmware Prior to 1.2.0.1.

Starting with firmware 1.2.0.1, the default per-port STP path cost was changed from a static value of 20000 to 0 (dynamic mode). In dynamic mode, path cost is automatically calculated based on link speed (e.g., 1G = 20000, 10G = 2000), allowing STP to correctly prefer higher-bandwidth links.

If a Switch was originally deployed on firmware prior to 1.2.0.1 and has since been upgraded, the old static default (20000) persists in the configuration. This prevents dynamic path cost from taking effect, which can cause STP to make incorrect forwarding decisions, such as blocking a 10G SFP link in favor of a 1G Cat6 link.

To prevent incorrect forwarding decisions from STP

When upgrading a Switch from firmware earlier than 1.2.0.1 to version 1.3.3-2 or later, ensure you perform a Factory Reset before beginning any configuration, whether through the standalone UI or via Access Points and Switches Management.

1. Upgrade the Switch firmware to 1.3.3-2 or later.

2. Perform a Factory Reset on the Switch.

3. Re-provision the Switch via Unified Management Access Points and Switches Management (Access Points and Switches Management will push the current configuration back to the Switch) or reconfigure via standalone UI.

If a Factory Reset is not performed, the per-port STP path cost will remain fixed at the legacy static value of 20,000 across all ports, there by preventing dynamic path cost calculation. At present, Unified Management Access Points and Switches Management does not push MST00 (CIST) per-port path cost settings to local Switches; this functionality is planned for a future Access Points and Switches Management release. Until such support becomes available, the recommended procedure to ensure correct STP path cost behavior is to upgrade the firmware and subsequently perform a Factory Reset, as outlined above.