BPDU guard

In an STP environment, switches, end stations, and other Layer 2 devices use Bridge Protocol Data Units (BPDUs) to exchange information that STP will use to determine the best path for data flow.

The BPDU guard, an enhancement to STP, removes a node that reflects BPDUs back in the network. It enforces the STP domain borders and keeps the active topology predictable by not allowing any network devices behind a BPDU guard-enabled port to participate in STP.

In some instances, it is unnecessary for a connected device, such as an end station, to initiate or participate in an STP topology change. In this case, you can enable the STP BPDU guard feature on the RUCKUS port to which the end station is connected. STP BPDU guard shuts down the port and puts it into an errdisable state. This disables the connected device's ability to initiate or participate in an STP topology. A log message is then generated for a BPDU guard violation, and a CLI message is displayed to warn the network administrator of a severe invalid configuration. The BPDU guard feature provides a secure response to invalid configurations because the administrator must manually put the interface back in service if errdisable recovery is not enabled.

Note: BPDU guard is supported on tagged ports as long as it is tagged on both sides to the same VLAN.