Free CCNA | Rapid Spanning Tree Protocol | Day 22 | CCNA 200-301 Complete Course

Introduction

In this tutorial, we will explore Rapid Spanning Tree Protocol (RSTP) and its Cisco proprietary version, Rapid Per-VLAN Spanning Tree Plus (Rapid PVST+). Understanding RSTP is essential for network design and troubleshooting, as it enhances the original Spanning Tree Protocol (STP), providing faster convergence and better network performance.

Step 1: Understand STP Version Comparison

Familiarize yourself with the differences between STP and RSTP. Key points include:

• STP: Standard Spanning Tree Protocol, slower convergence time.
• RSTP: Rapid Spanning Tree Protocol, significantly faster convergence.
• Rapid PVST+: Cisco's version that supports multiple VLANs.

Step 2: Learn RSTP Basics

Get an overview of RSTP:

• RSTP improves upon STP by reducing the time it takes for switches to reconfigure after a topology change.
• It uses the same fundamental concepts as STP but introduces new port states and roles.

Step 3: Familiarize with RSTP Port Costs

Understand how port costs are determined:

• RSTP uses port costs to influence the choice of the root bridge and the best path to that bridge.
• Costs are based on link speed.

Step 4: Compare STP and RSTP Port States

Review the port states in both protocols:

• STP Port States: Blocking, Listening, Learning, Forwarding, Disabled.
• RSTP Port States: Discarding, Learning, Forwarding.

Step 5: Examine RSTP Port Roles

Learn about the roles assigned to RSTP ports:

• Root Port: The port on a non-root bridge with the lowest cost path to the root bridge.
• Designated Port: The port on a network segment that has the lowest cost to the root bridge.
• Alternate Port: A backup path to the root bridge, becomes active if the root port fails.

Step 6: Understand UplinkFast and BackboneFast

Explore Cisco enhancements:

• UplinkFast: Allows a switch to quickly transition a blocked port to the forwarding state if the root port fails.
• BackboneFast: Speeds up convergence by allowing switches to quickly determine if the root bridge is still reachable.

Step 7: Review RSTP Port Role - Backup

Identify the backup port role:

• A port that can become a designated port if the current designated port fails.

Step 8: Configure RSTP in CLI

Learn how to configure RSTP using the command line interface (CLI):

1. Access the switch CLI.
2. Enter global configuration mode.
3. Use the command:

   spanning-tree mode rapid-pvst
   

4. Verify configuration with:

   show spanning-tree
   

Step 9: Analyze RSTP BPDUs

Use Wireshark to capture and analyze Bridge Protocol Data Units (BPDUs):

• Understand how BPDUs are used for communication between switches in RSTP.

Step 10: Configure RSTP Timers

Configure RSTP timers for optimal performance:

• Hello Timer: The interval between BPDUs.
• Aging Time: Time before a learned address is removed from the MAC address table.

Step 11: Identify RSTP Link Types

Differentiate between RSTP link types:

• Edge Link: Connection to an end device, bypassing the listening and learning states.
• Point-to-Point Link: Direct connection between two switches.
• Shared Link: Connection shared by multiple devices.

Conclusion

In this tutorial, we covered the Rapid Spanning Tree Protocol and its enhancements over traditional STP. Key takeaways include understanding port roles and states, configuring RSTP in a Cisco environment, and the importance of link types. For further learning, consider practicing with simulations or labs to deepen your understanding of RSTP and its application in real-world scenarios.