LPI Linux Certification in a Nutshell , Second Edition is an invaluable resource for determining what you need to practice to pass the Linux Professional Institute exams....

The Concise Guide to DNS and BIND provides you with the technical depth and expert-level information you need to understand and administer DNS and BIND. Domain Name System (DNS) is a distributed Internet directory service. It is used mainly to translate between domain names and IP addresses, and to control Internet email delivery....