Understanding STP Types in Networking (STP, RSTP, MSTP)

If you’ve ever managed switches, you know Spanning Tree Protocol (STP) is your best defense against network loops . Without it, redundant links could bring your entire LAN down!

Let’s quickly go through the five main STP types every network engineer should know

1. STP - IEEE 802.1D ​

This is the original Spanning Tree Protocol, the one that started it all.

• Provides loop prevention in Layer 2 networks.
• Has slow convergence (30-50 seconds).
• Best for small or legacy networks.

2. PVST / PVST+ ​

Per-VLAN Spanning Tree runs a separate STP instance for each VLAN.

• Allows better load balancing across links.
• PVST works with ISL; PVST+ adds 802.1Q support.
• Common in Cisco networks.

3. RSTP - IEEE 802.1w ​

Rapid Spanning Tree Protocol improves on classic STP.

• Much faster convergence (a few seconds).
• Compatible with standard STP.
• Great for modern, fast networks.

4. Rapid PVST+ ​

Combines the speed of RSTP with per-VLAN flexibility.

• One instance per VLAN (like PVST+).
• Ideal for Cisco-based enterprise networks.

5. MSTP - IEEE 802.1s ​

Multiple Spanning Tree Protocol is all about efficiency.

• Groups several VLANs under a single STP instance.
• Reduces CPU and memory load on switches.
• Best for large-scale, multi-VLAN networks.

Advantages of Using STP ​

• High redundancy and loop prevention
• Supports load balancing (especially PVST+)
• Efficient resource usage (RSTP < MSTP < Rapid PVST+)

Disadvantages ​

• Requires more configuration and understanding.
• Can be complex in multi-vendor or large VLAN setups.

Pro Tip ​

Choose your STP type based on network size, speed, and VLAN strategy:

• Small, simple network ➜ STP or RSTP
• Cisco VLAN-heavy network ➜ Rapid PVST+
• Large enterprise ➜ MSTP

 

Types of Spanning Tree Protocol (STP)