Writings on technology and society from Wellington, New Zealand

Thursday, July 19, 2007

A rose by any other name – how domain names work

Today on Radio New Zealand National I talked about domain names on the Internet, where they came from, what they are, how you can get one and what you should pay for one. My notes are below the split, and as usual, there are some links at the end.

Q: Domain names are the names we use for things on the Internet, right? How does all that work?

A: Yes, is an example of a domain name. We’ve talked in the past about how computers know each other by long numbers like international phone numbers. That’s how the core of the Internet was designed to work – with every machine knowing every other machine’s number. When the Internet was much smaller than it is now, there was a complete of list of machines on it that everybody shared. Obviously that’s not possible now – the Internet is a far too big, and the machines on it change every day, or more likely every second.

The naming system was added to provide a way to devolve the responsibility for naming computers out to people who might actually know what was going on their corner of the Internet.
That’s why names look the way they do – the right hand bit, like dot com or dot nz, is the least specific part, and they get more specific as you move from right to left. So, in, dot nz means that it’s a New Zealand name, co means that it’s a commercial body in New Zealand, RadioNZ is obviously the name of the company, and the dub dub dub is the name of the specific machine which serves web pages.

Q: The dub dub dub is optional, isn’t it? Why is that?

A: Yes. It’s a bit of an anachronism. The history there is that the Internet and the domain name system predates the World Wide Web – the famous three Ws – by quite a while, and that in the early days of the web, the web was just another service that people on the Internet offered, among others like FTP and Gopher, and the machine was named accordingly. These days the Web is overwhelmingly the most common information service that people offer on the Internet and so most companies have dropped the need for the dub dub dub on the front – their servers are just told to send any web traffic straight to the web server regardless. So, most web addresses will work without the www on the front, but not all of them – it depends on whether the particular server is set up that way. Any web masters or web mistresses listening out there, by the way, please do check your servers and make them accessible without the dub dub dub – why make your visitors type more than they need to?

Q: And what about the HTTP that you sometimes see on the front of web addresses?

A: That’s what’s called the protocol. It stands for HyperText Transfer Protocol, which is the name for the way in which web pages are packaged up and transported across the Internet. Quoting the HTTP – it needs to be followed by a colon and two forward slashes – tells your computer that it’s a web page you want, not some other kind of service. You don’t generally need to say the http bit though – your web browser just assumes that you want a web page and supplies the http automatically. But here are alternative services to http, like the ones I just mentioned – gopher and FTP. Gopher was a kind of primeval world wide web driven by menus. Every gopher page was either a list of pointers to other pages or a document. There was a network of gopher servers across the Internet. There’s only a handful left now.

Q: What happened to gopher?

A: The World Wide Web, in short. It does everything gopher did and a lot more besides, so all the gopher servers turned into web servers. Another protocol was FTP or file transfer protocol – you still see this around quite a bit. FTP is just a way of shipping files around the Internet. Of course, the Web can do this for you as well, but there are some advantages to FTP such as speed, and its easier to move files in both directions – from the server to your PC and vice versa.

Q: Why are some sites dot nz and other dot com?

A: Dot com is what’s called a generic – it’s not tied to a country. Dot NZ is very much the New Zealand space on the Internet. Other countries have their own, like dot AU for Australia or dot UK for the United Kingdom.

Q: So does that mean that a dot NZ site is in New Zealand?

A: No. It means that site has chosen a name in New Zealand, but the site itself could be anywhere.

Q: So how do you get a name in dot NZ?

A: Quite easily – in fact, it’s InternetNZ, the group I’m president of, which manages the dot NZ names. It’s a good idea to have your own name – you can make your email and your website look like they belong to you that way. My name is – that goes to my web site, and any email sent to that name ends up in with me. You get a name by asking an accredited dot NZ registrar. There’s a list on the Domain Name Commission’s web site at Most New Zealand ISPs are on the list.

Q: What’s the difference between a and a Are there others?

A: These are what are called second-level domains. We have them in dot NZ, as do lots of other countries like Australia and the UK. Some others like Canada and France don’t have a second level – everybody just registers their names directly under the country code, like say In New Zealand there are thirteen second level domains – is the most popular but there are others like, and Most are open second level names, like, meaning anyone can register a name in them, but some like are controlled, or moderated in the jargon, meaning that only, a specific community, such as parts of government can get access to the names.

Q: What does it cost to have your own domain name?

A: New Zealand names are all the same wholesale price – $1.50 per month plus GST, which is $18 a year. That’s a wholesale price – you have to deal with an accredited registrar to buy one, and they put a margin on to cover their costs. The actual cost you will pay ranges from $25 a year upwards. Ask your ISP what a name will cost you – if it’s more than, say, $40 a year, I’d ask what services it’s supplying for the extra and I’d be tempted to look at a different ISP or another registrar if they couldn’t give me a good answer.

Q: How many names are there on the Internet?

A: Millions! Somewhere over 70 million in dot com alone. In New Zealand we are nudging up towards 300,000 names – in May the number grew by over 5,000.

Q: So, about the names – how do you choose a name?

A: Creatively! I think it’s no accident that the seriously big web companies – Google and Yahoo – have, well, creative names. They don’t sound anything like the traditional bricks and mortar companies. But the really big web companies are less than 10 years old, they have ridiculous names which have become household names, and they are bigger than most traditional companies you have heard of.

One thing to watch out for, though – don’t just go out and register a name which is a household name already, like Coke or Adidas, unless you are sure you know what you are doing – big companies can be very protective about their trademarks and you might hear from their lawyers in short order.

Q: So how does the system work? What happens when you type a name into your computer?

A: Several things – the computer has to convert the name into one of the IP numbers that computers use to address each other across the Internet. It does that by using the domain name system. When you ask it to look up a name, the first thing your computer does is ask one of the thirteen root servers that anchor the whole global domain name system. Every computer just knows the IP addresses of the thirteen servers. In fact there are eighty or so root servers now, using a kind of deep magic called Anycast to split up some of the thirteen, so they are spread over the world. There are two in New Zealand, one each in Wellington and Auckland. Anyway, if you’ve asked for, say,, the root server will reply with the address of the name servers which handle dot NZ. And your computer will then go to one of those servers and ask it about, and when it gets an answer it will ask the next in the chain where is. And ultimately it gets back an IP address, which is just dandy because it can have a conversation with another computer once it knows the IP address.

Q: How does one computer talk to another once it knows the IP address?

A: The details of that are a topic for another conversation. But the important thing here is that communicating between numbered machines is something that is just built into the core of the Internet protocols – any machine on the Internet knows how to do it. But the domain name system gives us a way to have memorable names attached to those machine numbers.


The New Zealand Domain Name Commissioner, a list of New Zealand registrars, and a booklet on how to get a New Zealand domain name.

A Wikipedia article about gopher, and a link to a gopher site (works in Firefox, not Internet Explorer).

The locations of the root servers.

Domain name numbers for generic addresses and for dot nz.

posted by colin at 1:51 pm  

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