Configuring BPDU Filter on Cisco Switches
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.
STP
Spanning Tree Protocol, the loop-prevention mechanism that keeps Layer 2 networks stable. Articles tagged STP cover port roles and states, RSTP and MST, root bridge configuration, BPDU Guard and Root Guard hardening, and Cisco Catalyst troubleshooting.
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PortFast Configuration on Cisco Switches: When and How to Use It
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.
Configuring Rapid PVST+ on Cisco Catalyst Switches
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+.
How to Configure the STP Root Bridge on Cisco Switches
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.
802.1D vs PVST+ vs Rapid PVST+ vs MST: Comparing STP Variants
Five major STP variants exist today, each with different convergence speeds, VLAN handling, and design requirements. Understanding their differences is essential to choosing the right protocol for your network.
STP Path Cost and How Cisco Switches Calculate the Best Path
Path cost is the core metric STP uses to select root ports and designated ports. Understanding cost calculation, link speeds, and manual cost override is essential to designing networks with predictable failover behavior.
How STP Works: Root Bridge Election, BPDUs, and the Spanning Tree Algorithm
Root bridge election, BPDU exchange, and the spanning tree algorithm are the core mechanics of STP. This article walks through the entire process with configuration and show command output.
Understanding STP Timers: Hello, Forward Delay, and Max Age
STP timers control convergence speed, BPDU frequency, and failure detection. Understanding how hello, forward delay, and max age interact is essential to designing stable networks and troubleshooting convergence issues.
STP Port States: Blocking, Listening, Learning, Forwarding, and Disabled
STP port states control when a port begins forwarding traffic. The five states and their transitions define convergence time. Understanding state machine timers is essential to designing networks that recover quickly from failures.
STP Port Roles Explained: Root, Designated, Blocked, and Alternate
STP port roles determine which ports forward traffic and which block. Understanding root, designated, blocked, and alternate ports is essential to predicting network behavior and troubleshooting convergence issues.
Featured
What Is Spanning Tree Protocol (STP)? The Bridge Loop Problem Explained
Spanning Tree Protocol is the foundation of loop-free switched networks. Without it, redundant links create broadcast storms and MAC table corruption. This article explains the bridge loop problem and how STP solved it.
Cisco PVST Guide: Spanning Tree for Every VLAN
Master PVST (Per-VLAN Spanning Tree) on Cisco switches — learn configuration, root bridge design, port roles, and common troubleshooting tips.