STP

Root Guard blocks unauthorized root bridges on designated ports. Loop Guard prevents loops from unidirectional links on blocking ports. Both are essential for large campus networks.

BPDU Guard immediately error-disables ports that receive BPDUs, preventing rogue switches from corrupting your spanning tree. This article covers configuration, monitoring, and recovery.

BPDU Filter stops sending and receiving BPDUs on a port. Unlike other STP protection features, it's inherently dangerous and rarely used in production networks.

PortFast (edge port in RSTP) skips listening and learning phases, allowing hosts to reach the network in milliseconds instead of 30 seconds. This article covers per-interface configuration, global defaults, trunk ports, and critical use cases.

Rapid PVST+ (RSTP) replaces STP with a faster mechanism that converges in seconds instead of minutes. This article covers configuration, proposal/agreement handshakes, edge port usage, and migration from legacy PVST+.

The root bridge is the reference point for all STP calculations. Proper root bridge configuration is critical to predictable topology and optimal traffic flow. This article covers priority commands, macros, and design placement.