What is the command to enable BPDU filter on an access port?
At the global level, you can enable BPDU filtering on Port Fast-enabled STP ports by using the spanning-tree portfast bpdufilter default global configuration command. This command prevents interfaces that are in a Port Fast-operational state from sending or receiving BPDUs.
What is Spanning Tree BPDU filter enable?
The STP BPDU filter feature allows control of spanning tree participation on a per-port basis. It can be used to exclude specific ports from becoming part of spanning tree operations. A port with the BPDU filter enabled will ignore incoming BPDU packets and stay locked in the spanning tree forwarding state.
What is BPDU filtering?
BPDU filter is a feature used to filter sending or receiving BPDUs on a switchport. When configured globally all portfast enabled ports stop sending and receiving BPDUs, but if a BPDU is received on the port it gets out of the portfast state and normally participate in the spanning tree calculations.
What is BPDU guard and BPDU filter?
BPDU filter will prevent inbound and outbound BPDU but will remove portfast state on a port if a BPDU is received. On the other hand, BPDU Guard keeps an eye open for any BPDU’s entering the interfaces that are enabled this feature. The port will disable as soon as the first BPDU is received, by shutting the port down.
Why do we need a BPDU filter?
Bpdu filter will prevent inbound and outbound bpdu but will remove portfast state on a port if a bpdu is received. Enabling BPDU filtering on an interface is the same as disabling spanning tree on it and can result in spanning-tree loops.
Which commands can be used to enable BPDU guard on a switch?
BPDU guard can be enabled on all PortFast-enabled ports by using the spanning-tree portfast bpduguard default global configuration command. Alternatively, BPDU guard can be enabled on a PortFast-enabled port through the use of the spanning-tree bpduguard enable interface configuration command.
How do I know if my Cisco BPDU Guard is enabled?
To display the BPDU guard state, enter the show running configuration or the show stp-bpdu-guard command. For the BPDU status enter the stp-bpdu-guard command.
Is BPDU guard enabled by default?
By default, BPDU guard is disabled. Enter interface configuration mode, and specify the interface connected to an end station. When you globally enable BPDU filtering on Port Fast-enabled ports, it prevents ports that are in a Port Fast-operational state from sending or receiving BPDUs.