A closed intranet is nothing but a network that is not connected to the Internet. One would say that DNS is very simple to configure in relation to closed intranets. What is the problem then?

Your company uses the company.com domain, and you have very little difficulty in configuring your domain’s name server; in fact, you configure the primary name server for your company.com domain on one machine and the secondary one on another.

You direct all your clients’ resolvers to these name servers. The following figure shows a client asking the name server configured by you for a translation of the name server.company.com to its IP address:

Figure 9.1: Translation of the name server.company.com to its IP address

Everything is working fine until the client sends an incorrect request for server.ompany.com instead of the correct server.company.com (i.e., there is a one-character error).

Common mistakes like this result in additional time taken to find the server, and...