Linux Networking #2 🚀 : OSI Model 🧠 and TCP/IP Stack 🌐 💻

🧠 Conceptual Network Models Telegram: https://t.me/projectCD_Chronicles Conceptual models serve to standardize the functions of a network, dividing them into hierarchical levels, each with specific tasks. 📚 OSI Model (Open Systems Interconnection) It is a theoretical model composed of 7 layers, useful for understanding how networks work: Layer Name Main Function 1 Physical Transmission of raw bits over the physical medium (e.g., cables, RJ-45 connectors) 2 Data Link Communication between nodes, error control, MAC addresses (Ethernet, Wi-Fi) 3 Network Packet routing via IP addresses (IP, ICMP) 4 Transport End-to-end communication (reliable TCP, fast but not guaranteed UDP) 5 Session Management of sessions between hosts 6 Presentation Formatting, compression, data encryption (e.g., JPEG, SSL/TLS) 7 Application User interaction (HTTP, FTP, DNS) 🌐 TCP/IP Stack Practical and operational model used on the Internet, with 4 layers that simplify the OSI: TCP/IP Layer OSI Correspondence Main Function Network Access Layers 1 and 2 Interface with the physical medium Internet Layer 3 Addressing and routing (IP) Transport Layer 4 End-to-end communication (TCP, UDP) Application Layers 5, 6, 7 Application protocols (HTTP, DNS, etc.) 🛠️ Practical Example: `tcpdump` on Linux Command-line tool for analyzing network traffic: 🔍 In the output, you can observe: Layer 2: MAC addresses Layer 3: IP addresses Layer 4: TCP/UDP ports Layer 7: Part of the application content (e.g., DNS requests) #LinuxNetworking #NetworkingFundamentals #WiFi #TCPIP #LAN #TechTips #Networking101 #