Disable recursive DNS queries (Linux)

For information on recursive DNS, see What risks are associated with recursive DNS queries?.

Note: To perform this procedure, you must be the root user on your server.

To Disable Recursive DNS Queries

1. Connect to your server via SSH (more info).
2. Switch to the root user (more info).
3. Run the following commands:
   
   cd /tmp/
   wget -O rdnsfix http://products.secureserver.net/scripts/rdnsfix
   php -c /r rdnsfix