DNS Troubleshooting Guide

There are many reasons why a domain name may not be resolving to the server (i.e. when people enter a domain and do not arrive at the correct server). This guide offers troubleshooting tips for overcoming typical domain resolution issues and also gives a simplified explanation of how DNS works.


DNS Troubleshooting Checklist

Check Name Servers

Check to make sure your name servers are correct. There are several, free online tools that will allow you to view domain DNS, including name servers. Examples of these tools include:

You can also view the correct name servers in a variety of places, including the HostGator welcome email and the cPanel for Shared web hosting accounts.

For more information on name servers and how to find them, please read the following article:

Check the Validity of the Domain

Make sure the domain is registered and not expired; this can be checked with a Whois lookup tool. If the domain is expired, it will need to be renewed. If it is not registered, it will need to be registered. New domains can be registered at portal.hostgator.com

For more information on how to renew an expired domain or soon-to-be expired domain, please refer to the following article:

Check if the DNS Glue is Good

DNS Glue can be disrupted by the name server records not being listed properly in the DNS files. For Reseller accounts, VPS and Dedicated Servers, it is possible that the name servers are not properly added to the DNS zone. You can check by going to an online DNS viewing tool to see if the DNS tool reports that there is "No Glue" next to the name servers listed.

For more information on DNS Glue and how to repair bad glue, please read the following article:

Check if the A Records are Correct

Be sure that the A records point to the correct IP. Although this will most likely be correct if cPanel configures it automatically, there are a number of reasons why this could be incorrect. This sometimes happens when you are not using our name servers or if you manually made changes to the DNS zones.

For information on how to make changes to your DNS records, such as A records, MX records and CNAME records, please read the following article:


Understanding Propagation

When you make certain changes to the DNS, such as name server changes, A record changes, MX record changes, etc., it takes time for those changes to propagate or update throughout the internet worldwide. Some people will see the change instantly and some will see the change within up to 48 hours, depending on what DNS record was changed.

Note: If the name servers have recently been changed, this means the changes need to propagate. However, always check the settings to make sure that it is setup as you expect. Just because the name servers were recently changed, does not mean they were changed correctly.

What is Propagation and Why Does it Take So Long?

The reason why propagation takes so long is because computers cache (remember) the old setting for a period of time. What is happening is that your computer, as well as servers on the internet, only check for DNS changes every so often. They typically do not check to see if the settings have changed every time you make a request. They assume the DNS is the same as the last time they checked.

For name server changes, your computer and servers on the internet will cache this information for up to 48 hours. For other changes, such as A records, MX records, CNAME records, etc., it will remember the old settings for up to 4 to 8 hours before checking to see if the settings have changed.

Can I See My Site Before it Propagates?

You can see your site sooner by modifying your hosts file. By modifying your hosts file on your local computer you can have your computer ignore the DNS of your domain and instruct it specifically which server to load data from.

For more information on how to modify your hosts file, please refer to the following articles:


Propagation Alternative Strategies

For users who wish to view their site before the propagation period ends, the following options listed below are available as feasible work-around options so that the site can be viewed regardless of propagation status.

Flush DNS

If you cannot see your site after changing the name servers due to propagation, it may be because your computer is remembering the old name server settings. You may be able to see your site sooner by flushing the DNS on your computer, assuming your internet service provider is not also caching the DNS.

For instructions on how to flush your DNS, please refer to the following knowledge base article:

If flushing the DNS does not work, then either the name servers have not been updated or your internet service provider (ISP) is caching the DNS. If your ISP is caching the DNS, you will have to wait until propagation finishes to view your site via your domain name. This can take up to 48 hours.

Modifying the Hosts File

If the options above do not work, there is a more technical way to see your site sooner by temporarily changing your hosts file on your computer. This will force your computer to go to our server's IP address for the most recent information. This does not actually fix the DNS; rather, it lets you see the site with your domain name, regardless of what the DNS says.

For more information on how to make these changes, please refer to the following article: