Core networking concepts explained in plain English — IP addressing, the OSI model, switching, routing, and how devices actually talk to each other.
ARP quietly resolves every IP address on your network into a MAC address, but most guides skip how it actually works. See the request-reply cycle, your ARP table, and the spoofing risk in one place.
Still relying on old WHOIS habits? RDAP vs WHOIS is no longer close: ICANN ended the WHOIS mandate in 2025, and most registries have already made the full switch to RDAP.
TCP vs UDP decides how every packet you send behaves. See the handshake, the speed tradeoff, which real ports use each protocol, and why HTTP/3 quietly rewrote the rules you learned.
How DHCP works decides whether your device gets online at all. See the four-message DORA handshake, the lease timers running behind your connection, and the one setting home labbers get wrong.
Want to know how long to transfer a file before the download starts? Your file manager’s estimate is often wrong. The bits-versus-bytes gotcha is usually why, and the math that fixes it is simple.
VPN vs. proxy vs. Tor — all three hide your IP, but protect you very differently. Compare encryption, speed, anonymity, and cost to pick the right tool.
TL;DR — The Short Version The OSI model is a 7-layer reference framework that describes how data travels between applications across a network. It is not software you install or a protocol you configure. The seven layers, bottom to top: Physical, Data Link, Network, Transport, Session, Presentation, and Application. Mnemonic: Please Do Not Throw Sausage … Read more
Master the common network ports every IT pro should know, organized by category for TCP and UDP. Includes port security, how to check open ports, and why HTTP/3 now puts HTTPS on UDP 443.
TL;DR — Key Takeaways A MAC address is a unique 48-bit hardware identifier for a network interface. It is how devices find each other on a local network. MAC addresses work at Layer 2 and look like A4:83:E7:2F:5B:10. That is six hex pairs split by colons or hyphens. Find yours in system settings or with … Read more