DNS is an Application layer protocol that is used as a standard naming service for the Internet. This naming service was designed for name-to-address resolution for TCP/IP networks. This naming service uses the hostname as an index to locate IP addresses in the database.
A DNS domain contains name servers that are used to maintain information about the domain. The DNS environment has three types of name servers: master server, slave server, and a cache server.
The master server maintains a database that contains files similar to the /etc files. These files contain the IP addresses of machines in a particular domain. The slave servers act as backup servers and contain the same information as the master server.
The cache server is used to manage ...