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@@ -55,7 +55,7 @@ Download [PDF version](DevOps%20Roadmap.pdf).
 
 ### 4. Learn Networking & Security
 
-- [OSI Model Explained](https://www.youtube.com/watch?v=dV8mjZd1OtU) <sup>FREE</sup>
+- [OSI Model Explained](https://www.cloudflare.com/en-gb/learning/ddos/glossary/open-systems-interconnection-model-osi/) <sup>FREE</sup>
 - [Computer Networking: A Top-Down Approach](https://www.amazon.com/Computer-Networking-Top-Down-Approach-7th/dp/0133594149) <sup>book</sup>
 - [TCP/IP and Networking Fundamentals for IT Pros](https://www.pluralsight.com/courses/tcpip-networking-it-pros) <sup>Pluralsight course</sup>
 - [DevSecOps : Master Securing CI/CD | DevOps Pipeline](https://www.udemy.com/course/devsecops/) <sup>Udemy course</sup>