Domains, how do they work?

DomainsWe all use them all the time, but what is a domain, really?

Alot of people ask me who sells a domain? Isn’t it just a made up string? How can anyone claim to own any made up string and sell it as a product?

Well, compare it to the address of your home. It’s not a “thing” you buy. You buy the house, and the address is attached to the house – or rather, your property. As with domains you could just make up an address, but it would be of no use if nobody recognized the made up address as an actual address.. Well, this metaphore only gets us so far.

So we’ve established that a domain is really nothing. That’s not quite true. When you register a domain, an organization or company responsible for that domain (assigned by IANA) create an entry in their database labeled with your made up name, let’s say it’s jorno.org.

Jorno.org is stored in the database of Public Interest Registry, or PIR for short. PIR has been granted by IANA (The Internet Assigned Numbers Authority) and ICANN (Internet Corporation for Assigned Names and Numbers) to take care of the .org zone. A zone is comparable to a database. The zone contains all the domains registered under the .org-TLD (Top Level Domain). The entry contains information about the domain. Creation date, expirydate, information about the owner etc.

And here it is yet again; the owner? How can anyone own a made up name? Nobody can really claim any name.. The domain names are hired for one or more years at the time. A domain owner pays for the sole right to use that domain and “the rules of engaging with the internet” demands all connected parties to respect its authority. Sure you can convince your computer that microsoft.com leads to you local IP 127.0.0.1 and have fun with your own private world view, but if you want to be on the same page as the rest of the world, you’ll want your computer to ask the the .com registry -> microsofts name servers -> microsofts web server what’s really going on with Microsoft today.

So what you pay for is really for the worlds recognition that the domain name you’ve made up is yours and leads to the services of your choosing for as long as you renew the domain.

Domain vs. IP

There’s a misconception that domains are in place so that we don’t need to remember an IP-address. Domains do more than that for us. Large web servers contains several hundred or even thousands of different web sites, all located at the same IP-address. So how do you tell them apart? When you send a request for a website to a web server, the domain is a part of the request. The server recognize the domain and fetches the correct site as a response.

What now?

Another question I get a lot is; so can I make an email address now?

No, not yet.. As mentioned before, a domain is like a street address. Let’s say you buy an empty property with only trees and rocks. You’ve got the land and you’ve got the street address, but there’s nothing there. You need to put up a house (or a post box or whatever..). Ergo, you’ll need to put up an email service or a web service. The neat thing with domains is that you can route the traffic to anywhere you’d like and change it whenever you want (unlike a street address). A web service can be anything. It can be email, web pages, remote desktop, IP-phone, digital TV etc.

When an email service is established you direct the “email traffic” of your domain to the email server IP-address running you email using DNS.

The what?

We now arrive to the world of DNS (Domain Name Server).

In the case of jorno.org, we’ve established that PIR has all the info about the domain. PIR has also stored what name servers, or DNS servers are to be considered authorities for where the various services are located. There are two name servers for jorno.org (ns1.uniweb.no and ns3.uniweb.no). When your tried to reach jorno.org it ultimately got the correct IP-address og jorno.org web server (91.207.158.141) from one of these name servers. The reason there are two name servers is just to make sure one is always available.

The DNS servers ns1.uniweb.no and ns3.uniweb.no both contains the same information:

Name             Type     Content
jorno.org        A        91.207.158.141
www.jorno.org    A        91.207.158.141

This will direct all web traffic to the IP 91.207.158.141 when both jorno.org or www.jorno.org is requested. Same principle for email:

Name             Type     Content
jorno.org        MX       mx01.uniweb.no

My MX-record is actually something else, but we keep it simple here.

To recap..

  • PIRs zone for jorno.org lets everybody know ns1.uniweb.no and ns3.uniweb.no are the authorative name servers.
  • ns1.uniweb.no and ns3.uniweb.no’s zone lets everybody know 91.207.158.141 is the location of jorno.org’s website.

Long story short; a domain sort of is something.

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