Blog

Modern LANs run on high-speed switches, PoE, structured cabling, and Wi-Fi 6/7 APs. Here is a clean walkthrough of the components and how they fit together.

IPv4 gives every networked device a 32-bit address split across classes and subnets. Here is how IPv4 addressing works, why it still runs the internet, and its limits.

The OSI model's seven layers explain how data moves from application to wire. Here is each layer, the key protocols, and how to use the model for troubleshooting.

Straight-through cables connect PC to switch or router; crossover cables connect like to like. Here is the pinout, color code, and when Auto-MDIX makes it moot.

IP routing is how routers pick a path and forward packets between networks. Here is the routing table, next hop, and longest-prefix match in simple terms.

Enabling SSH on a Cisco router or switch takes a hostname, domain name, RSA keys, a local user, and vty line login. Here is the full config plus verification.