Domain Name System (DNS) servers help us to resolve friendly computer names, such as www.packtpub.com, to a less human-friendly IP address, such as 83.166.169.231. In this way, mere humans can access many computer systems by guessing the address or the DNS name. In the early days of UNIX computers, where access was limited to a few academic systems, hostnames were distributed by Network Information Service (NIS); a central computer maintained a single file that mapped hostnames to IP addresses. This file was then pushed out to client subscribers. Although this worked, it was clearly not scalable.

In 1988, the first release of the DNS server was developed by four graduates from UCB (the University of California, Berkeley). This software in now maintained by the ISC (Internet Systems Consortium). Even today, it's still known as Berkeley Internet Name Domain (BIND).

On Red Hat Enterprise Linux 7.1, the version of the DNS server or bind that is shipped is 9.9.4. Once installed...