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Spanning Tree Protocol

(also STP)

Spanning Tree Protocol definition

The Spanning Tree Protocol is a network protocol that prevents loops in a local area network. A loop causes serious problems in a network. For instance, if a switch receives a broadcast frame and sends it out on all other ports, and this frame is returned to the switch on one of these ports, the switch will repeatedly broadcast this frame, causing a broadcast storm and consuming the network's bandwidth.

STP prevents such scenarios by creating a loop-free logical topology in networks with potentially redundant paths.

See also: Ethernet

History of elliptic-curve cryptography

Radia Perlman invented the Spanning Tree Protocol in 1985 while working for the Digital Equipment Corporation (DEC).

DEC submitted Perlman's STP as a standard to the IEEE, ratified as IEEE 802.1D in 1990. Since its development, STP has become a core component of network design and has been implemented in almost all Ethernet switches.

Over time, several enhancements have been made to the original STP to improve its efficiency and response times. These include Rapid Spanning Tree Protocol (RSTP, IEEE 802.1w), which reduces the time it takes for the protocol to react to changes in the network topology, and Multiple Spanning Tree Protocol (MSTP, IEEE 802.1s), which allows for multiple spanning trees over different VLANs in the same network.

Dr. Radia Perlman's work on STP has been pivotal in developing modern networking, and she's often referred to as the “Mother of the Internet.”