This guide will help you modify the DNS settings of ClearOS so that the system does not use linear methods for DNS resolution. By default, ClearOS will query, in turn, each DNS server listed until it gets a result. Using this method, ClearOS will query all DNS servers listed and reply with the first answer it receives. This method can increase speed, but leaves you vulnerable to bad messages if your fastest DNS server has the wrong information. You may also NOT want to use this method if using the AD Connector unless you have take provisions to move the resolution of your realm records to the DNS server.
To modify the setting, SSH into your server or access the command line using the console. Use your favorite text editor (like nano, or vi) to modify the following file:
In this file, insert a '#' sign in front of the line 'strict-order'. So that it looks like this:
Save the file with this setting. Then restart the local DNS caching server:
service dnsmasq restart