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
Credits
About the Authors
Preface
Country Codes and RIRs
Index

10.2 Name Server Installed on Firewall


If we want to have two separated zones for the company.com domain, the primary Internet server is usually located on the firewall and the secondary Internet server on the computer of the Internet provider. A separate pair of primary/secondary servers is set up within the intranet.

And again, we have two possibilities. The first one enables the translation of the whole Internet on the intranet, and the second one enables the translation of only the intranet zone on the intranet.

10.2.1 Translation in Intranet—Whole Internet

We have two separate pairs of name servers as shown in the following figure:

Figure 10.3: Company DNS zone is divided into two independent zones with the same domain name company.com, but with a different content

One of the pairs is on the intranet, while the other is on the Internet.

The first problem is that an application that is run on the firewall (for example, proxy) needs information on the intranet company.com zone, although it...