Linux provides a highly transparent and programmable networking stack, allowing you to see exactly how packets traverse interfaces, bridges, and routing tables. This post introduces the foundational tools and concepts for inspecting and configuring Linux’s data plane directly, rather than relying on abstracted models.

This blog post provides a structured overview of computer networking fundamentals, organized around the OSI model and real-world practices. It begins with the basics of the OSI and TCP/IP stacks, then explores each layer’s function—from physical transmission and link-layer protocols like Ethernet and ARP, to IP addressing and routing at the network layer, and reliable communication via TCP and UDP at the transport layer. The application layer section covers protocols such as HTTP, DNS, and SMTP. It also explains core routing algorithms (like OSPF and RIP), and addresses NAT and firewall principles for secure Internet access. Designed for both students and practitioners, the post balances theoretical clarity with engineering relevance.