What are DNS Servers?

When your domain name is registered it is delegated to a pair (usually, although more than 2 DNS servers can be used) of DNS servers.  These DNS servers hold DNS records which tell the Internet “world” the physical location of the web server that holds your website and the mail server which handles your email.  The physical location of these servers comes in the form of an IP Address e.g. 210.48.108.200.  As it would be difficult to have to remember the IP Address of every website we wanted to visit, domain names were created to make this task a little easier.  So basically, DNS servers just translate the ‘easy to remember’ domain names into the ‘hard to remember’ IP Addresses, so that Internet traffic can be directed to your website or to your email address.

Every ISP on the Internet has their own DNS Servers which direct the people who are using that ISP to the location they are looking for.  For example, if Xtra is your ISP, then you would usually use Xtra’s DNS servers to find the website you type into your browser address bar.

What are DNS Records?

DNS Records are the individual records held on the DNS Servers, that specify where different traffic for your domain name should be directed.  For example, if you have a website your DNS Servers should hold ‘A’ Records for both www.yourname.co.nz and yourname.co.nz (without the www) that point to the IP Address of the web server where your website resides.  If you have email service set up, you should also have DNS ‘MX’ Records, which point mail for your domain name to the server which handles your mail.  There are several other types of DNS Records which are used, but the main ones are ‘A’ and ‘MX’ Records.

Authoritative DNS Servers

There should only be one set of DNS servers that are responsible (authoritative) for directing Internet traffic for your domain name.  These should be the DNS servers that are held in the Domain Name Registry database against your domain name.  For example, the domain name yourname.co.nz is delegated to the DNS servers ns.freeparking.co.nz and ns2.freeparking.co.nz in the NZ Registry database, therefore these two DNS servers are ‘authoritative’ for yourname.co.nz.

Common DNS Problems...

No authoritative DNS Records

This means that a domain name has been delegated to a set of DNS Servers at the Registry, but those DNS servers do not hold any ‘authoritative’ DNS Records for that domain name.  For example, if yourname.co.nz had been delegated to ns.freeparking.co.nz and ns2.freeparking.co.nz at the Registry, but those DNS servers had no  ‘A’ or ‘MX’ Records for yourname.co.nz, this would result in all the Internet traffic looking for the location of yourname.co.nz receiving a DNS error.

DNS servers holding incorrect ‘authoritative’ Records

This is usually caused when a domain name is transferred from one Internet Provider to another, and the losing Provider does not remove their ‘authoritative’ DNS records.  For example, if the domain name yourname.co.nz had been hosted at Xtra (so Xtra held ‘authoritative’ DNS records for it) but then the DNS servers at the Registry were changed to WebFarm’s.  If Xtra did not remove their ‘authoritative’ DNS Records, all the people who connect to the Internet via Xtra, and therefore use Xtra’s DNS servers for direction, would still be sent in whatever direction Xtra’s DNS Servers pointed them, instead of being ‘referred’ to WebFarm’s DNS servers for the new (and valid) location of yourname.co.nz.

DNS ‘Time to Live’ and Caching

When a domain name is delegated to a new set of DNS Servers, or even when the DNS Records for a domain name are changed on the same set of DNS Servers, these changes take time to propagate through the Internet.  Propagation is the process where all of the other DNS Servers on the Internet ‘learn’ of the new ‘authoritative’ DNS Servers, or the new IP Address location of the website etc.  Propagation time can vary depending on what ‘time to live’ has been set on the previous authoritative DNS Records, or how long each ISP caches (saves) DNS Records they have ‘learnt’, before looking to see if a more up to date DNS Record exists.  Unfortunately, it is usually out of your control how long propagation of a DNS Server change takes, due to these ‘time to live’ and caching factors.   However, if you are making a change to a DNS Record, you can change the ‘time to live’ setting (and allow that time to propagate) before making the Record change, so that your changes propagate more quickly when they are made.

Changing DNS Servers at WebFarm

If you wish to change the DNS servers for a domain name registered with WebFarm, you can do this through the My Account section on our website.  Just log in, select the domain name you wish to change the DNS servers for (if more than one domain exists in your account) and then use the ‘Change Domain Servers’ tool to replace (overwrite) the existing DNS Servers with the new ones.  Make sure you do not add the new DNS Server names to the existing ones, as this will result in your domain name being delegated to two different sets of DNS servers, which will cause problems.

Changing DNS Records at WebFarm

The ‘Edit DNS Records’ tool under My Account on our website will allow you to change the ‘A’, ‘MX’, ‘CName’ and ‘TXT’ Records for your domain name.  For ‘A’ Records you will need to know the IP Address of the web or mail server you need your domain name to point to, or in the case of ‘MX’ Records, you will need the name of the mail server.  If you only have an IP Address for a mail server, we recommend pointing the MX Record to mail.yourname.co.nz, and then creating an A Record to point mail.yourname.co.nz to the IP Address of the mail server.