Ubuntu® Linux® Secrets

Chapter 20. DNS Server

Secrets in This Chapter

• What Is DNS?

• Using Ubuntu DNS Client Programs

• Configuring a DNS Server

What's in a name? Plenty, if you're a Montague or are using the Internet. How would you react if your favorite product was advertised on television stating, "Just visit our web site at 198.182.196.56 for more information"? Unfortunately, humans do not process numbers as well as computers do. To compensate for that, systems administrators use names to identify their computer systems. The domain name system (DNS) was developed to help humans easily locate computer names on the Internet. If you choose to let your ISP handle your domain name and email, you may not need to know the details about DNS configurations, but it might not be a bad idea to know how DNS works in general (just in case of any problems). This chapter discusses where DNS came from, why it is so vital to email and web operations, and how you can configure your Ubuntu server to utilize it either as a client or as a DNS server.

History of Computer Names

Back in the old days when the Internet was small (just a few hundred computers) it was not too complicated to locate another computer. Each Internet computer had a database of hostnames and IP addresses. Internet hostnames could be anything the administrator desired—Fred, Barney, Acct1, anything. There was a central clearinghouse for keeping track of new computer names and addresses. Once a week or so, a systems administrator would download a new copy of the ...