Updated: April 2021

Preface

There are several reasons why you might need at least two DNS servers for serving your sites:

• You purchased a domain name from a domain registrar. To delegate the domain, many registrars require the domain zone to be served by at least two name servers residing in different IP subnets.
• You have several hosting servers, and you have not grown enough to use the products like PPA or PA, but you want to use a single set of name servers for all the domains you host.
• You want to have your own name servers and not depend on third parties.
• You want the WHOIS records for your domains to list your name servers.

Usually you would set up a couple of name servers in the Master/Slave mode. Then you create domain zones on both servers, but administer resource records of the domain zones only on the master server. The secondary (slave) server automatically downloads the changes from the master. Thus, you always have two active name servers with the same set of domain zones and resource records.Continue reading