How Domain Name Services (DNS) Works

When you type in a name like “www.yourdomain.com” into a browser, your PC has to look up the name in order to get a numeric “IP address” that actually points to the server that hosts your website. This is called domain name resolution and involves several steps that happen behind the scenes.

First, let’s back up and look at how domain names are registered. When you want to register or “buy” a domain name, you must go through one of many registrars. Registrars can sell domain names and other services, but they all have to check one master database that maintains a list of all currently registered names for the entire world.

There are actually several different databases of domain names (and that goes beyond the scope of this article), but there are a set of about a dozen “root” name servers that keep track of where all the domain name information is actually stored.

Once registered, your domain name must be assigned to at least two domain name servers. These servers are responsible for answering queries about your domain. For example, if you have a website, then www.yourdomain.com will be an entry in the database, and it will point to a numeric “IP address” which is the address assigned to the server where your website is hosted.

Without the primary and secondary name servers, even if your domain is registered, no one will be able to reach your website or send you email.

Many registrars also offer free primary and secondary name server space for your domain, but the primary and secondary can be hosted by anyone who runs name server services. Information Analytics hosts hundreds of domain names on our internal name servers.

Once the primary and secondary name servers have been assigned, that information is stored in the root name servers, which are located all over the world. When a request comes in for your domain, the root server doesn’t return the address of your website, it returns the address of the primary and secondary name servers. Then your PC contacts the primary/secondary which returns the actual numeric address.



Lastly, your PC opens a connection to the web or mail server, using the numeric address it was given. Name servers also store or “cache” lookups, to reduce network traffic. If you need to change the numeric address of a server (for example, if you’re moving your website or email to another service provider) you’ll need to change the address in the primary/secondary, and that change could take hours to propagate. The cache has a timeout value, which could be minutes to hours to days, depending on how it was configured. The old entries will stay in the local cache, perhaps giving out the wrong answer, until the cache timeout is reached.

Common DNS Problems

The most common issues that come up relate to confusion about where a domain is hosted or registered.

#1 – Changing Registrars

You can move your domain from one registrar to another, without changing the primary and secondary name servers – IF those name servers are not provided by your registrar. If we (Information Analytics) hosts your domain on our primary and secondary name servers, you could move your domain from Network Solutions to Enom and there would be no loss of service, and no one would no the difference. However, if you use Network Solutions’ name servers, if you move the domain to Enom, you would have to switch to using Enom’s name servers and reenter all your addresses (i.e., www, mail) in order to keep your website and email working. This process is not automatic when changing registrars.

#2 – Changing Primary/Secondary Name Servers

You can change your primary and secondary name servers (when changing registrars or web hosting providers). First, you’ll need to make sure that the new primary/secondary servers are preconfigured with your addresses, such as www.yourdomain.com. Next, you’ll need to go through your registrar account (enom, godaddy) to change the names of the primary and secondary. Third, after waiting at least 24 hours, ask your former provider to discontinue primary/secondary services for your domain.

#3 – Changing the address of your website or email

It is not necessary to move your primary/secondary name service or change domain registrar, just to point www to a new host. However, if your current host provides ALL your services as part of a package deal (registrar, primary/secondary, web and email) and you are closing your account with them, then it would be necessary to change all of the above services. However, if you were (for example) using Network Solutions for all services and decided to keep your domain name with them but move your web and email, you could drop down to domain registration only in your account with them, but point primary and secondary to your new host, and then let your new host manage DNS for you.

Summary

Domain name services can be very confusing, due to the fact that there could be at least three parties involved in making it all work. If in doubt about which services are hosted by which providers, contact us- we can check for you and give you a list of providers. In order to make any changes to your domain registration, please make sure that you keep your registrar account up to date – without a valid email address it can be very difficult to regain control of your domain name.