ALERT

[LAST CHANCE] Data Layer: Modern Business, Defined

Bridge Protocol Data Unit (BPDU)

Definition - What does Bridge Protocol Data Unit (BPDU) mean?

A bridge protocol data unit (BPDU) is a data message transmitted across a local area network to detect loops in network topologies. A BPDU contains information regarding ports, switches, port priority and addresses.

BPDUs contain the information necessary to configure and maintain spanning tree topology. They are not forwarded by switches, but the information is used by switches to calculate their own BPDUs for information passing.

Techopedia explains Bridge Protocol Data Unit (BPDU)

When devices are initially attached to switch ports, they do not start data transmission immediately. Instead, they moves through different states while BPDU processing determines the network topology. A topology change notification (TCN) BPDU informs other switches of port changes. They are injected into the network by a non-root switch and propagated to the root. When a TCN is received, the root switch will set a topology change flag in its normal BPDU. This flag is propagated to all other switches to instruct them to rapidly age out their forwarding table entry
switches.

When a root receives the TCN BPDU, it transmits a configuration BPDU message on all the ports with topology change flag set to 1. Switches that receive this BPDU on the root port filter the database and generate their own configuration BPDUs on designated ports. This propagates down the tree to the end of the path.

Techopedia Deals

Connect with us

Techopedia on Linkedin
Techopedia on Linkedin
Tweat cdn.techopedia.com
"Techopedia" on Twitter


'@Techopedia'
Sign up for Techopedia's Free Newsletter!

Email Newsletter

Join thousands of others with our weekly newsletter

Resources
The 4th Era of IT Infrastructure: Superconverged Systems
The 4th Era of IT Infrastructure: Superconverged Systems:
Learn the benefits and limitations of the 3 generations of IT infrastructure – siloed, converged and hyperconverged – and discover how the 4th...
Approaches and Benefits of Network Virtualization
Approaches and Benefits of Network Virtualization:
Businesses today aspire to achieve a software-defined datacenter (SDDC) to enhance business agility and reduce operational complexity. However, the...
Free E-Book: Public Cloud Guide
Free E-Book: Public Cloud Guide:
This white paper is for leaders of Operations, Engineering, or Infrastructure teams who are creating or executing an IT roadmap.
Free Tool: Virtual Health Monitor
Free Tool: Virtual Health Monitor:
Virtual Health Monitor is a free virtualization monitoring and reporting tool for VMware, Hyper-V, RHEV, and XenServer environments.
Free 30 Day Trial – Turbonomic
Free 30 Day Trial – Turbonomic:
Turbonomic delivers an autonomic platform where virtual and cloud environments self-manage in real-time to assure application performance.