When you make certain changes to the DNS, such as nameserver 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 nameservers 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 nameservers 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 nameserver 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 viewing the site via an alternate URL, also known as a temporary URL. A temporary URL is a combination of a server IP and the control panel username.
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 nameservers due to propagation, it may be because your computer is remembering the old nameserver 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.
Flush DNS If flushing the DNS does not work, then either the nameservers 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.