What Is Bpdu Guard Used For

The only devices which can reliably create and transmit bpdu s are switches our main aim to have a predictable topology and not allow other switches outside our control onto our network. This document explains the portfast bridge protocol data unit bpdu guard feature.

Spanning Tree Bpduguard

Even if you receive a superior bpdu from another switch root guard will prevent that switch from becoming the root bridge.

What is bpdu guard used for. Portfast bpdu guard prevents loops by moving a nontrunking port into an errdisable state when a bpdu is received on that port. If a switch port which is configured with spanning tree protocol stp portfast feature it must be connected to an end device for exampe. The bpdu guard disables interfaces as a preventive step to avoid a potential bridging loop.

Bpdu guard feature is used to protect the layer 2 spanning tree protocol stp topology from bpdu related attacks. This feature enhances switch network reliability manageability and security. There are no specific requirements for this document.

Bridge protocol data units bpdus are frames that contain information about the spanning tree protocol stp. Once bpdu guard is enabled it will keep an eye open for any bpdu s entering the access ports. Bpdu guard puts an interface configured for stp portfast into the err disable state upon receipt of a bpdu.

This feature is one of the spanning tree protocol stp enhancements that cisco created. Spanning tree bpdu guard is one of the features that help you protect your spanning tree topology bpdu guard prevents loops if another switch is attached to a portfast port. A switch sends bpdus using a unique source mac address from its origin port to a multicast address with destination mac 01 80 c2 00 00 00 or 01 00 0c cc cc cd for cisco proprietary per vlan spanning tree.

The bpdu guard feature is used to protect the spanning tree domain from external influence. Workstation server printer etc. Bpdu guard and root guard are enhancements to spanning tree protocol stp enhancements that improve the reliability of the protocol to unexpected events.

Bpdu guard feature must be enabled on a port that should never receive a bpdu from its connected device. When bpdu guard is enable on an interface it is put into an error disable state basically shutdown if a bpdu is received on the interface. When you enable bpdu guard on the switch spanning tree shuts down portfast configured interfaces that receive bpdus instead of putting them into the spanning tree blocking state.

Bpdu guard is disabled by default but is recommended for all ports on which the port fast feature has been enabled. Root guard for spanning tree can be used to prevent a certain switch from becoming the root bridge.

Cisco Switches Stp Bpdu Guard Youtube