I want to upgrade DNS (Primary & Slave) could someone guide me to do this upgrading successfully ( 1. What are the steps to be consider before upgrading? 2. Which first server to start upgrade ? 3. What is the possiblities of failed upgrading? 4. How to Rollback of the Bind 8.2.2-P5 if the upgrade of 8.4.7 failed? -- With Regards Yasser Al-Shaqsi