Complete Protocol dictionary, glossary and reference
802.1D is an IEEE specification which defines Spanning-Tree Protocol (STP). STP is a link management protocol that provides path redundancy while preventing undesirable loops in the network. For an Ethernet network to function properly, only one active path can exist between two stations. Loops occur in networks for a variety of reasons. The most common reason for loops in networks is a deliberate attempt to provide redundancy -- in case that one link or switch fails, another link or switch can take over.