OSI 7-Layer Model Explained with TCP/IP Mapping | Hands-On Linux Demo

Learn the OSI 7-layer model and how it maps to the TCP/IP 4-layer model — then see each layer in action with real Linux terminal commands. In this tutorial, you'll learn: • The 7 OSI layers (Physical, Data Link, Network, Transport, Session, Presentation, Application) and the protocols that live at each layer • How the OSI model maps to the TCP/IP 4-layer model (Link, Internet, Transport, Application) • Where Ethernet, IP, TCP/UDP, HTTP, SSH, and DNS actually sit in the network stack • Use `ip link show` to inspect Layer 2 MAC addresses • Use `ip addr show` to verify Layer 3 IP addressing • Use `ss -tulnp` and `/etc/services` to identify Layer 4 transport ports and services • Use `curl -sI http://httpbin.org/get` and `arp -n` to see Layer 7 application traffic and the L2/L3 boundary Who this is for: developers, sysadmins, DevOps engineers, and IT students who want a practical, no-fluff understanding of networking fundamentals. Drop a comment: which layer confused you the most when you first learned networking? Subscribe for weekly hands-on Linux, networking, and DevOps tutorials. #osi #osimodel #tcpip #networking #linux #devops #sysadmin #networkingfundamentals