Spanning Tree Protocol (Stp) Bpdu Guard; Displaying Stp Information - Dell PowerConnect B-RX Configuration Manual

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IEEE 802.1D Spanning Tree Protocol (STP)

Spanning Tree Protocol (STP) BPDU guard

STP protection provides the ability to prohibit an end station from initiating or participating in an
STP topology. The STP BPDU Guard is used to keep all active network topologies predictable.
The spanning-tree protocol detects and eliminates logical loops in a redundant network by
selectively blocking some data paths and allowing only some data paths to forward traffic.
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.
When a Layer 2 device is powered ON and connected to the network, or when a Layer 2 device goes
down, it sends out an STP BPDU, triggering an STP topology change.
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 Brocade port to which the end station is connected. Brocade's STP BPDU Guard feature
disables the connected device's ability to initiate or participate in an STP topology change, by
dropping all BPDUs received from the connected device.
Enabling STP protection
You can enable STP BPDU Guard on a per-port basis.
To prevent an end station from initiating or participating in STP topology changes, enter the
following command at the interface level of the CLI.
BigIron RX(config) interface ethe 2/1
BigIron RX(config-if-e1000-2/1)# spanning-tree protect
This command causes the port to drop STP BPDUs sent from the device on the other end of the
link.
Syntax: [no] spanning-tree protect
Enter the no form of the command to disable STP protection on the port.

Displaying STP information

You can display the following STP information:
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All the global and interface STP settings
Detailed STP information for each interface
STP state information for a VLAN
STP state information for an individual interface
BigIron RX Series Configuration Guide
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