Description
In one or two paragraphs, describe the operation of STP.
Explanation & Answer
The Spanning Tree Protocol (STP) is a network protocol that ensures a loop-free topology for any bridged Ethernet local area network. The basic function of STP is to prevent bridge loops and the broadcast radiation that results from them. Spanning tree also allows a network design to include spare (redundant) links to provide automatic backup paths if an active link fails, without the danger of bridge loops, or the need for manual enabling/disabling of these backup links.
Spanning Tree Protocol (STP) was originally standardized as IEEE 802.1D, most recently in 802.1d-1998, but deprecated as of 802.1d-2004 in favor of Rapid Spanning Tree Protocol (RSTP). As the name suggests, it creates a spanning tree within a network of connected layer-2 bridges (typically Ethernet switches), and disables those links that are not part of the spanning tree, leaving a single active path between any two network nodes.
STP is based on an algorithm that was invented by Radia Perlman while she was working for Digital Equipment Corporation.