All switches constantly communicate with their neighbors in the LAN using bridge protocol data units (BPDUs). All switches then select their best connection towards the root bridge for forwarding and block other redundant links.
When implemented in a network, STP designates one layer-2 switch as root bridge. This preferred link is used for all Ethernet frames unless it fails, in which case a non-preferred redundant link is enabled. The spanning-tree algorithm then blocks forwarding on redundant links by setting up one preferred link between switches in the LAN. Every link between switches, and in particular redundant links, are catalogued. To avoid the problems associated with redundant links in a switched LAN, STP is implemented on switches to monitor the network topology. : 388 If redundant links are used to connect switches, then switching loops need to be avoided.
#Radia perlman mac#
: 386 However, this connection configuration creates a switching loop resulting in broadcast radiations and MAC table instability. The need for the Spanning Tree Protocol (STP) arose because switches in local area networks (LANs) are often interconnected using redundant links to improve resilience should one connection fail. Switches with Spanning Tree Protocol implementation in a local area network (LAN) Link aggregation protocols such as LACP will bond two or more links to provide fault tolerance while simultaneously increasing overall link capacity.
While STP is still in use today, in most modern networks its primary use is as a loop-protection mechanism rather than a fault tolerance mechanism. STP was originally standardized as IEEE 802.1D but the functionality of spanning tree (802.1D), rapid spanning tree (802.1w), and multiple spanning tree (802.1s) has since been incorporated into IEEE 802.1Q-2014. RSTP was designed to be backwards-compatible with standard STP. RSTP provides significantly faster recovery in response to network changes or failures, introducing new convergence behaviors and bridge port roles to do this. In 2001, the IEEE introduced Rapid Spanning Tree Protocol ( RSTP) as 802.1w. STP is based on an algorithm that was invented by Radia Perlman while she was working for Digital Equipment Corporation. Spanning tree also allows a network design to include backup links providing fault tolerance if an active link fails.Īs the name suggests, STP creates a spanning tree that characterizes the relationship of nodes within a network of connected layer-2 bridges, and disables those links that are not part of the spanning tree, leaving a single active path between any two network nodes. The basic function of STP is to prevent bridge loops and the broadcast radiation that results from them. Perlman is the only person to be named in both issues.The Spanning Tree Protocol ( STP) is a network protocol that builds a loop-free logical topology for Ethernet networks. Twice named as one of the 20 most influential people in the industry by Data Communications magazine: in the 20th anniversary issue (1992) and the 25th anniversary issue (1997). Honorary Doctorate, Royal Institute of Technology (June 28, 2000) Silicon Valley Intellectual Property Law Association Inventor of the year (2003) Recipient of the first Anita Borg Institute Women of Vision Award for Innovation in 2005 USENIX Lifetime Achievement Award (2006) National Inventors Hall of Fame induction (2016) Also, innovations in security including distributed algorithms resilient against malicious participants, assured expiration of data from storage, and PKI trust models. In particular, link state routing, spanning tree, and TRILL.
Inventor of innovations that make today's network protocols scalable, robust, and self-organizing.
0 kommentar(er)
