It is helpful for you to familiarize yourself first with the different types of DNS servers before deciding on which DNS configuration to adopt.
Highlighted below are some common DNS server types. Each DNS server carries out a specific function, and your choice of DNS configuration should, as a matter of fact, be based on your requirements and the problems you want to resolve.
- Authority-Only DNS Servers: Authority-only DNS servers only provides answers or solutions to queries that they are responsible for. They are fast for resolving the queries in their zones, but they neither cache results nor respond to recursive queries. Take for instance, the military or scientific organizations may configure their internet to only release DNS information/data that is only related to their field/industry.
- Caching DNS Servers: The primary function of Caching DNS Servers is to attend to recursive queries from users. Unlike Authority-Only DNS Server that handles only a specific, limited range of queries from its specific zone information, Caching DNS Server tends to deal with widespread recursive queries using its broad base of public DNS information. And to avoid sending multiple queries to different cache servers, a caching DNS Server immediately caches the results of the initial query, and makes them available to the users. Caching DNS server is the most common server for internet users. When people send a query to the internet, irrespective of the operating system they may using, they are mainly requesting the answers to their queries through Cashing DNS servers.
- Forwarding DNS Servers: As their names imply, Forwarding DNS Servers act as forwarding agents for recursive queries. They don’t, on their own, resolve any recursive queries but pass them on to the appropriate servers that will provide solutions/answers to the queries. This kind of servers can also be used as “a filter”, in the sense that sensitive internal information is forwarded to the private servers within an organization while the information meant for external audience is routed through the public servers.
- Combined Servers: It is possible to combine the three different servers described above so as to achieve a well-connected and functional Domain Name System. However, when different servers are combined into a single server, it may cause a problem of information/data overload that may heat up the servers.
- Public and Private Servers: The public servers handle the data/information for the public audience, while the private servers are used by companies that want to pass the information around for their internal staff only. To purely maintain a private server, it is advisable that all references to it must be removed from the public servers.
- Master or slave servers: A master server handles more zone files than the slave server, even though both of them handle mainly authoritative data/information in their zones. However, a slave-server deals with information obtained from one of the zone files of the master server. In a certain circumstance, a master server can become a slave server, depending on the amount of zone files they can handle. Technically, every DNS server has, at least, two zones.
So, you should configure your DNS based on your needs and requirements.