What's the role of DNS?

What is DNS? What's the role of DNS? We hang on the Internet all day, the estimates for these problems are also somewhat vague, DNS is the domain Name system, the abbreviation, is a core service of the Internet, DNS, domain name resolution system, is not a simple service, and a wide range of global domain name resolution system, by a number of DNS servers and DNS member machine composed of such a computer organization. As a distributed database that can map domain names and IP addresses to each other, it makes it easier for people to access the Internet without remembering the number of IP strings that can be read directly by the machine. Below we will come together to study the relevant knowledge about DNS, I hope to help you!

What is DNS?

Generally speaking, DNS is the abbreviation of the domain name System of the computer, which is composed of a parser and a domain name server. A domain name server is a server that holds the domain name and corresponding IP address of all the hosts in the network and has the ability to convert domain names to IP addresses. Where the domain name must correspond to an IP address, an IP address can correspond to multiple domain names at the same time, but the IP address does not necessarily have a domain name. If you are the webmaster this sentence very good understanding, for example, there is a server corresponding to an IP, and this server can be placed on multiple sites, different sites can have multiple domain names, such as our "Router network" as an example: through Webmaster tools can check the station's server, and this server placed on how many stations, The following figure:

Is this a good way to understand what DNS means? The domain Name system uses a hierarchical structure similar to that of a directory tree. The domain name server is a server in client/server mode, and it has two main forms: the primary server and the forwarding server. The process of mapping a domain name to an IP address is referred to as "domain resolution." In the Internet domain name and IP address is one-to-one (or more to one), although the domain name is convenient for people to remember, but the machine can only understand each other IP address, the transformation between them is called Domain name resolution, domain name resolution needs to be specialized domain name resolution server to complete, DNS is the server for domain name resolution. DNS names are used in TCP/IP networks such as the Internet to find computers and services through a user-friendly name. When a user enters a DNS name in an application, the DNS service can resolve the name to other information associated with it, such as an IP address. Because, you enter the Web site, is through the domain name resolution system to find the corresponding IP address, so as to access the Internet. In fact, the end point of the domain name is IP.

As we all know, when we surf the internet, usually input is the URL, in fact, this is a domain name, and our computer network computers can only use IP address between each other to identify each other. Domain name (URL) just quite with the number, just for the convenience of memory and increase.

What is a DNS server?

A DNS server is a domain Name System or domain name service, or a header, domain Name system that assigns domain name addresses and IP addresses to hosts on the Internet. The user uses the domain name address, the system will automatically convert the domain name address to the IP address. The Domain Name service is an Internet tool that runs the domain Name System. The server that executes the domain name service is called a DNS server that answers the query of the domain Name service through a DNS server.

Friends who have used the router settings will not be unfamiliar with DNS server settings, when we need a fixed IP address, we need to enter the DNS server address, as shown in the following figure:

In the above DNS server address, we generally fill in the local Network business DNS IP address, why to fill in the Local Network service server DNS address? On the above we also introduced, computer and computer access are through IP to communicate, Our computer needs to communicate with the external computer needs to have its own DNS, that is, the network business, because we are away from the local network network connection is the closest, so the local service provider DNS address settings can maximize the Exchange speed of the computer and the network. Different regions of the country, such as telecommunications or netcom have different DNS IP address, so if you need to fix the local IP need to fill in the Local Network service server DNS address, if you do not know to fill in the most do not go to fixed IP address, select Automatic Access can be, if you need to contact the network or the Internet to inquire, Improper settings will result in Web pages can not open, such as the common QQ can not open the Internet page phenomenon!

The role of DNS in the domain environment:

1. DNS standard naming (domain naming);

2. Support DC (when creating DC, have corresponding DNS support);

3. Locate the DC (when joining the domain, help the earth person find the DC).