STP BPDU TX Filter

The Spanning Tree Protocol Bridge Protocol Data Units Transmit Filter (STP BPDU TX) stops the device from sending STP BPDUs on a port, while still processing any BPDUs received on that port.

Feature Overview

When the STP BPDU TX Filter is enabled on an interface, the device stops transmitting STP BPDUs on that port. However, the interface continues to forward data traffic normally. Despite stopping BPDU transmissions, the port continues to forward data traffic normally. It also continues to receive and process any BPDUs that arrive on the port.

Since this feature only affects outgoing BPDUs, existing protection features such as STP BPDU Guard continue to work as usual, reacting to any unexpected incoming BPDUs.

Requirements

This feature has no special hardware or software requirements for feature enablement or usage.

Considerations

Consider the following when configuring and using this feature:

  • This feature is enabled on RSTP Admin Edge ports by default. This does not apply to legacy configurations. If you are upgrading a device with existing RSTP Edge port settings, this feature is not enabledy by default. You can enable it manually.
  • When a port is set up as an RSTP edge port, the BPDU transmission suppression is turned on automatically. This happens because edge ports usually connect to end devices and are not expected to be part of the spanning-tree setup. You can still turn off this automatic suppression if you need the port to transmit BPDUs for a specific reason.
  • The STP BPDU TX Filter cannot be enabled on a port that is configured with the RSTP admin PT2PT MAC setting. These two features are mutually exclusive on the same interface.

Best Practices

RUCKUS suggests the following best practices regarding STP BPDU transmit filtering:

  • Turn on the STP BPDU TX Filter on ports that connect directly to end devices (such as computers or residential gateways) and are not meant to participate in the spanning-tree setup.
  • Do not enable this feature on ports that connect to other switches or to your network's core. These ports need to send and receive BPDUs to correctly build and maintain the spanning tree.
  • It is recommended to enable the STP BPDU TX Filter in conjunction with BPDU Guard on RSTP edge ports connected to non‑STP‑capable devices. This ensures protection against unauthorized BPDU reception while suppressing BPDU transmissions.

Prerequisites

  • Ensure that the 802.1w port parameters are not configured on a point‑to‑point link for all VLANs. For more information, refer to the spanning-tree 802-1w command in the RUCKUS FastIron Command Reference. If enabled, this configuration must be removed before enabling the STP BPDU TX filter.

In this section:

  1. Enabling STP BPDU TX Filter
    The Spanning Tree Protocol Bridge Protocol Data Units Transmit Filter (STP BPDU TX) feature stops the device from sending STP BPDUs on a port, while still processing any BPDUs received on that port.
Parent topic: Spanning Tree Protocol