Topic Overview
Networking
OSI, TCP/IP, subnetting, VLANs, NAT, firewalls, reverse proxies.
OSI and TCP/IP Models — What Every Developer & Sysadmin Should Know
Practical comparison of the 7-layer OSI model and 4-layer TCP/IP model, packet encapsulation, and bottom-up network debugging techniques.
IP Subnetting and CIDR in 10 Minutes — A Practical Guide
Complete beginner guide to IPv4 addresses, CIDR prefix notation, calculating usable hosts, subnet masks, RFC 1918 private ranges, and CLI tools.
NAT and Port Forwarding — A Beginner's Guide to Router Networking
Understand SNAT, DNAT (Port Forwarding), Hairpin NAT loopback, avoiding CGNAT traps, and safely hosting services from a home or office network.
Reverse Proxy Basics — One Front Door for All Web Services
Complete beginner guide to reverse proxies, forward vs reverse proxies, SNI routing, upstream headers (X-Forwarded-For), TLS termination, and choosing between Caddy and Nginx.