Book Image

DNS in Action

By : CP Books a.s.
Book Image

DNS in Action

By: CP Books a.s.

Overview of this book

The Domain Name System is one of the foundations of the internet. It is the system that allows the translation of human-readable domain names into machines-readable IP addresses and the reverse translation of IP addresses into domain names. This book describes the basic DNS protocol and its extensions; DNS delegation and registration, including for reverse domains; using DNS servers in networks that are not connected to the internet; and using DNS servers on firewall machines. Many detailed examples are used throughout the book to show perform various configuration and administration tasks.
Table of Contents (16 chapters)
DNS in Action
About the Authors
Country Codes and RIRs

4.1 DNS Database

The basic assets of DNS are DNS databases and well configured name servers that manage these databases. The DNS protocol, which uses Resource Records (hereinafter RRs) in its queries and responses, was described in Chapter 2. RRs are primarily managed by hostmasters in disk files in primary name servers in a text format. These disk files are called DNS databases.

DNS databases are stored in files in the primary name server. Their content is loaded into memory at startup as shown in the following figure:

Figure 4.1: Program named finds out information about DNS databases in the named.boot file during startup

A DNS database consists of individual files that are specified as the last parameters of the individual commands of the named.boot configuration file. A database on a disk may contain the following types of data:

  • Authoritative data for the administered zone: This must start with the SOA record. This data can only be kept in the primary name server. A secondary name server...