Understanding how the DNS server works and its processes

The service provided by the DNS server is the task of converting the host name and domain name to an IP address. Why do I need to convert the hostname and domain name to an IP address? This is because when a client on a network accesses a resource on a server, the user enters the browser's address bar with the easy to remember host name and domain name. The connection between computers on the network is accomplished by the unique IP address that each computer has on the network, which requires a resolution between the user's easily remembered address and the address that the computer can identify, and the DNS server acts as an important role in address resolution. Next I will take you into the DNS world, detailed understanding of how the DNS server works and its process, I hope to be able to bring some help to friends.

Understanding the DNS Service

DNS is the abbreviation for the domain Name System, a computer and network service naming system that organizes domain hierarchies. When a user enters a DNS name in an application, the DNS service can resolve this name to the IP address information associated with this name.

Users like to use network services in the browser's address bar to enter the use of host name and domain name, such as computer.bookshop.com, because such a name is more easily remembered by the user. However, the computer uses an IP address to communicate on the network. To enable communication between network computers, the service provided by the DNS server is to map the computer or service name used by the user to an IP address.

The work process of the DNS service

When a DNS client needs to query the name used in a program, it queries the DNS server to resolve the name. Each query message sent by the client includes 3 messages to specify the question the server should answer.

The specified DNS domain name, which is represented as a fully qualified domain name (FQDN).

The specified query type, which can specify resource records based on type or as a specialized type of query operation.

The specified category for the DNS domain name.

For DNS servers, it should always be specified as an Internet category. For example, the specified name can be a fully qualified domain name for the computer, such as hosta.hello.company.com, and the specified query type is used to search for an address resource record through that name. The system will use DNS query as a client to the server two parts of the problem, such as "for the computer named Hostname.hello.company.com, you have address resource records?" When a client receives a reply from the server, it reads and interprets the address resource record of the answer to understand the IP address of the computer it asks questions by name.