After you update your domain's name server settings, DNS propagation can sometimes take from 24 to 48 hours to complete. During this time, you cannot use your domain name. However, you can bypass DNS and view your web site by using a shared URL or the hosts file.
This is the recommended method, because you do not have to modify any configuration files on your local computer.
A2 Hosting provides shared URLs that enable you to access your web site without using its domain name. The URL you use depends on the type of account you have, and which A2 Hosting server hosts your account. To view the correct shared URL for your account, log in to the A2 Hosting Customer Portal at https://my.a2hosting.com. Alternatively, for information about how to determine the shared URL for your account, please see this article.
Another method for bypassing DNS is to use the hosts file on your local computer. The hosts file contains domain name to IP address mappings. These mappings mimic the function of a DNS server, and allow you to “trick” your computer into associating a domain name with a particular IP address.
To use the hosts file to bypass DNS for your domain:
This starts Notepad with the elevated privileges necessary to open, modify, and save the hosts file. Note that in Notepad's Open dialog, you must use the All Files filter to see the hosts file.
When you open the hosts file, you should see an entry that resembles the following line:
To create a new mapping for your domain, add a line to the file as follows:
Replace the IP address with your A2 Hosting server's IP address, and replace example.com with your web site's domain name. You can obtain your account's IP address by logging in to http://my.a2hosting.com.
Save the hosts file and exit the text editor.
To test the configuration, restart your web browser and go to http://example.com, where example.com is your domain name. You should see your web site's main page (assuming you have created some content).
For more information about the hosts file, please visit http://en.wikipedia.org/wiki/Hosts_(file).