24. DNS/BIND: Tracking Domain Names and Addresses
DNS (Domain Name System) maps domain names to IP addresses, and vice versa. It reduces the need for humans to work with IP addresses, which, with the introduction of IPv6, are complex. The DNS specification defines a secure, general-purpose database that holds Internet host information. It also specifies a protocol that is used to exchange this information. Further, DNS defines library routines that implement the protocol. Finally, DNS provides a means for routing email. Under DNS, nameservers work with clients, called resolvers, to distribute host information in the form of resource records in a timely manner as needed. This chapter describes BIND (Berkeley Internet Name Domain) version 9, a popular open-source implementation of DNS. Part of the Red Hat Linux distribution, BIND includes the DNS server daemon (named), a DNS resolver library, and tools for working with DNS. Although DNS can be used for private networks, this chapter covers DNS as used by the Internet. |