#networking

Three blocks of addresses were quietly set aside in 1994 with no explanation for the numbers, an opposition RFC titled 'Considered Harmful' predicted decades of pain, and the lead objector ended up co-signing the winning standard. Your router's default address is the armistice line.

The web's most famous number has a beloved origin story involving an office at CERN where the first server lived. The web's own pioneers call the story hogwash. The real answer is duller, older, and better: the digits are a sentence, and you can read them.

The first tool anyone reaches for when the network dies was written in one evening in 1983 by a man thinking about submarines. The acronym everyone quotes for it was invented by someone else, after the fact, and the author's response to it was better than either story.

One man reserved it in 1981 with a single table row and his own initials as the only justification. The reason it was 127 and not anything else was never written down, and the address block it sits in is large enough to give every person in the Netherlands their own loopback.

A network port is a numbered endpoint that lets one host run many services at once. The word traces from the Latin for a gate or harbour, through the general computing sense of a connection point, into the TCP/IP port formalised by Jon Postel and Vint Cerf in the early ARPANET RFCs.

Before it filtered packets, a firewall was a literal wall — a fire-resistant barrier in buildings from the 1850s, then the iron bulkhead behind a vehicle's engine. The networking sense borrowed the metaphor in the late 1980s and was cemented by Cheswick and Bellovin's work at Bell Labs.

A WireGuard tunnel to a Hetzner VPS sent 670 KiB and received nothing. The firewall had an ALLOW rule for port 51820. Both facts were true — because the rule said TCP and WireGuard is UDP. A debugging war story, and the method that found it: bisect the packet path.

Lou Montulli invented the web cookie at Netscape in June 1994 to give a stateless protocol a memory. The name is borrowed from the Unix "magic cookie" — an opaque token a program hands around — and the privacy story started almost immediately.

Spam means junk because of a 1970 Monty Python sketch in which Vikings chant "SPAM" until it drowns out all conversation. The term moved through MUDs and Usenet to email, and Hormel — which trademarked SPAM in 1937 — eventually made peace with the lowercase generic use.

Bluetooth is named after a 10th-century Danish king, Harald "Bluetooth" Gormsson, who united warring tribes — the analogy Jim Kardach drew when he proposed it as a codename in 1996. The logo is a bind-rune of the king's initials. The codename was never meant to ship.

Tatu Ylönen wrote SSH at Helsinki University of Technology in July 1995 after a password-sniffing incident. Thirty years later it is the default remote-access protocol on every Unix-like operating system, including Windows. Almost nothing else in security tooling has lasted as long unchanged.