DNS & BIND Cookbook

Chapter 9. Resolvers and Programming

Introduction

Resolvers are considerably easier to configure than name servers. A BIND resolver supports just a few configuration directives:

domain

Sets the resolver’s local domain name

search

Sets the resolver’s search list and, implicitly, the local domain name

nameserver

Configures the resolver to query a remote name server

sortlist

Configures the resolver to sort certain A records to the beginning of responses

options

Controls miscellaneous aspects of the resolver’s configuration, such as timeouts

Windows resolvers support configuration of a similar set of parameters: at least the local domain name, search list, and remote name servers to query. This chapter includes recipes for configuring each of these aspects of a resolver’s behavior, for both BIND and Windows resolvers. It also includes several sample programs that demonstrate how to use the invaluable Net::DNS module to send queries, request zone transfers, and send dynamic updates from a Perl program.

Configuring a Resolver to Query a Remote Name Server

Problem

You want to configure a resolver to query a name server running on a particular remote host.

Solution

On a host running a BIND resolver, add a nameserver directive to the resolv.conf file. The resolv.conf file (note that there’s no “e” on the end of “resolv”) usually lives in the /etc directory; if it doesn’t exist, create one with your favorite editor. Specify the address of the remote name server as the single argument to the nameserver ...