Networks
Signals, addresses, names, routes and encryption – worked throughout on one real network failure.
Networking From Zero - Signals, Ethernet, MAC, ARP and DHCP
You will be able to say what a network actually is, and name the four jobs every network must do no matter how it is built.
24,029 words/104 min read24IP Addresses, Private and Public, NAT and Carrier-Grade NAT
You will be able to say exactly what an IP address labels, and why it is not a label for a device and not a label for a person.
21,284 words/93 min read25DNS - From a Name to an Address
You will be able to explain why the internet needs a naming system at all, and what people did in the years before it existed.
19,944 words/87 min read26Packets and Routing
You will be able to explain why data is chopped into small pieces at all, instead of being sent as one long stream, and name the four separate reasons.
16,910 words/74 min read27Traceroute Decoded - Reading Your Own Path
You will be able to explain why there is no "show me the route" command in the internet protocol, and why traceroute is a trick rather than a feature.
17,755 words/77 min read28TCP, Ports, and Why a Timeout Is Evidence
You will be able to say exactly what the internet's basic delivery service promises, and the much longer list of things it does not promise.
16,078 words/70 min read29Why Mobile Data Worked, and the Diagnostic Method
You will be able to state the difference between "the site is down" and "I cannot reach the site", and say who is affected by each.
20,994 words/91 min read30How the Internet Was Built
You will be able to tell the story of long-distance messaging from signal fires to fibre, in order, with correct names and years.
17,115 words/74 min read31Wireless - WiFi, Bluetooth, Cellular and GPS
You will be able to explain what a radio wave is and why an antenna has the length it has, and work out the wavelength of any band in your head.
18,217 words/79 min read32TLS, HTTPS and the Web Stack
You will be able to write a complete HTTP request by hand, byte by byte, and read a real response header block without guessing at any line.
18,034 words/78 min read33The OSI and TCP/IP Models, Retrofitted to Your Own Session
You will be able to say why networks are built in layers at all, what each layer is allowed to know, and what it is forbidden to know.
14,405 words/63 min read34Firewalls, VPNs, CDNs, IPv6 and the Gaps
You will be able to say exactly what localhost, 127.0.0.1 and 0.0.0.0 each mean, and why 0.0.0.0 means two different things depending on where you write…
26,934 words/117 min read