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CCNA Course Lecture Notes on STP

May 23, 2025

Jeremy's IT Lab CCNA Course - Lecture Notes

Introduction

  • Course Overview: Free, complete course for the CCNA.
  • Engagement Requests:
    • Subscribe, like, comment, and share the video.
    • Download the practice lab from the video description.
    • Consider using Boson’s NetSim for the CCNA for additional practice.
    • Preview of NetSim lab included at the end.

Lab Instructions

  • Preparation:
    • Turn off link lights in Packet Tracer to avoid revealing interface states.
    • Review lecture video concepts (e.g., bridge ID, root cost) if needed.

Lab Exercise

Spanning Tree Protocol (STP)

  1. Identify the Root Bridge

    • Compare bridge priorities and MAC addresses.
    • SW3 is the root bridge with the lowest priority (24577).

  2. Determine Spanning Tree Port Roles

    • SW3 Interfaces: All designated ports (since SW3 is the root bridge).
    • Finding Root Ports:
      • Each switch must have a single root port based on root cost.
      • SW1: F0/4 is the root port (tie-breaker: SW3's port ID).
      • SW2: G0/1 is the root port (lower root cost via G0/1).
      • SW4: G0/2 is the root port.

  3. Collision Domain Designation

    • Determine designated and non-designated ports.
    • SW1's F0/3 and SW2's F0/3 are non-designated (connected to root).
    • SW1's F0/1 and F0/2 are non-designated (higher root cost).
    • SW2's F0/1 and F0/2 are designated (lower root cost).

  4. CLI Commands

    • SW3: Verify using SHOW SPANNING-TREE, all interfaces designated and forwarding.
    • SW1: Verify F0/4 as root port, other interfaces blocking.
    • SW2: Verify G0/1 as root port, F0/1 and F0/2 designated.
    • SW4: Verify G0/1 as designated, G0/2 as root port.

  5. Additional Commands

    • SHOW SPANNING-TREE DETAIL: More detailed information.
    • SHOW SPANNING-TREE SUMMARY: Number of interfaces in each STP state.

Boson NetSim Lab Preview

  • CCNA Exam Topics: Does not cover spanning tree configuration (only describe/identify).
  • CCNP ENCOR Topics: Includes spanning tree configuration.
  • NetSim Features:
    • Spanning tree labs available for CCNP.
    • Example lab: Spanning Tree Protocol – verifying spanning tree execution, priority, and port states.

Conclusion

  • Recommendation: Use NetSim for hands-on practice.
  • Call to Action:
    • Subscribe, comment, like, and share.
    • Tips and BAT (Basic Attention Token) accepted via Brave browser.

Full transcript