DNS is used to translate hostnames into IP addresses. When DNS Servers are misconfigured, they can be used to conduct DDOS attacks using your dedicated server. We recommend that all public DNS servers be configured not to permit recursive DNS queries. This configuration will still allow DNS for your domain names to work properly, but will prevent abuse.
On Windows machines, you can disable recursive DNS:
Open Server Manager
Expand Roles -> DNS Server -> DNS -> (Your Server’s Name)
Right-click on your server name, choose Properties
On the Advanced tab, select Disable recursion (also disables forwarders)
Click OK
On Linux machines, there are a few common DNS Servers:
Open your BIND configuration file
In the options section, make sure you have recursion no and additional-from-cache no
Restart BIND after making any changes
Unfortunately, there is no straightforward way to disable this within DNSMasq. You would either need to modify the DNSMasq configuration so that it no longer listens on public IP addresses, or firewall off UDP port 53 to all hosts except your desired ones.
If, for some reason, you cannot make the necessary changes and you are not hosting your DNS, we would suggest that you firewall off all incoming UDP port 53 traffic.