STOP Unauthorized Plugs: 3 Violation Modes EXPLAINED
Learn how to protect your Ethernet network from unauthorized access by configuring port security on a Cisco switch! In this free CCNA course segment, we cover:
• Why Ethernet ports lack built-in authentication and common attack methods (e.g., Shark Jack, rogue switches, rogue Wi-Fi APs)
• Port security basics: MAC-based filtering, default limits, and violation modes (shutdown, restrict, protect)
• Step-by-step CLI demo: enabling port security on GigabitEthernet1/0/1,
observing learned MACs, and simulating violations with extra devices
• Understanding MAC address tables vs. port-security tables, and advanced
options (static MAC entries, sticky MAC)
• Limitations of dynamic learning and tips for persistent, enterprise-grade security
Whether you’re studying for CCNA or hardening your corporate LAN, this tutorial will empower you to prevent unauthorized plugs and unwanted traffic.
// Playlist to CCNA Course REFERENCE //
https://www.youtube.com/watch?v=tj3yCZWOWYc&list=PLw6kwOJVj3MbMZ8B72ZgUryj8OSETC0ds
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// MENU //
00:00 – Ethernet Bypass Explained
00:42 – Accessing the Switch via Ethernet Port
03:03 – Unauthorised Devices on the Network
03:35 – CCNA Course Overview with Real Examples
06:48 – How to Enable Port Security
07:56 – Port Security Demo
10:28 – Understanding MAC Addresses
12:55 – Fixing “Err-Disabled” Port State
15:35 – Using ‘shutdown’ and ‘no shutdown’ Commands
15:59 – Testing Port Security in Action
17:47 – Final Thoughts & Key Takeaways
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Disclaimer: This video is for educational purposes only.
#ccna #networking #security
David Bombal
Want to learn about IT? Want to get ahead in your career? Well, this is the right place! On this channel, I discuss Linux, Python, Ethical Hacking, Networking, CCNA, Virtualization and other IT related topics. This YouTube channel has new videos upload...