Spanning Tree Protocol

Spanning Tree

Spanning Tree Protocol (STP) is a network protocol that creates a loop-free logical topology for Ethernet networks by blocking redundant links. It prevents network loops that can cause "broadcast storms," which overwhelm a network and bring it down. STP ensures there is only one active path between any two devices and automatically reroutes traffic through a backup link if an active one fails, thus providing network redundancy and stability

• Prevents network loops: STP is designed to prevent loops that occur when there are multiple active paths between switches. Loops cause data packets to circulate endlessly, leading to a broadcast storm that can crash the network.
• Creates a single active path: STP builds a logical tree topology and blocks redundant links, leaving only one active path between any two network devices.
• Provides redundancy: While blocking redundant paths to prevent loops, STP maintains these paths as backups. If an active link fails, STP will automatically enable a blocked port to restore connectivity without manual intervention.
• How it works: Switches use special messages called Bridge Protocol Data Units (BPDUs) to communicate with each other. They exchange information to elect a "root bridge" and then determine the best path to that root bridge. Ports that are not part of the optimal path are placed in a blocking state.
• Standardization: STP is an IEEE 802.1D standard. Modern variations like Rapid Spanning Tree Protocol (RSTP) provide faster convergence times when a network change occurs

References: https://en.wikipedia.org/wiki/Spanning_Tree_Protocol