DNS (Domain Name Server) is a server that converts domain names and their corresponding IP addresses. DNS stores a table of domain names and their corresponding IP addresses to resolve the domain names of messages. A domain name is the name of a computer or group of computers on the Internet, used to identify the electronic location (sometimes also geographic location) of the computer during data transmission. A domain name is composed of a string of names separated by dots, usually including the organization name, and always includes a two to three letter suffix to indicate the type of organization or the country or region where the domain is located.
necessity
After registering a domain name and purchasing hosting services, you need to resolve the domain name to the purchased host in order to view website content. In the vast majority of cases, after the DNS domain name server resolves the domain name, it cannot immediately see the website content, but it takes several hours, or even one or two days, to open your website.
Analysis process
To understand why domain name resolution takes so long, it is necessary to understand the process of domain name resolution and the role of DNS servers.
Every computer on the Internet is assigned an IP address, and data transmission is actually carried out between different IP addresses. Including the computers we use when surfing the internet at home, they are also assigned an IP address after connecting to the internet, which is mostly dynamic. That is to say, if you turn off the modem and then turn on the internet again, your internet access will be randomly assigned a new IP address.
A website server is essentially a computer connected to the internet, but it is more suitable as a server in terms of configuration and placed in a data center to maintain a low temperature, low dust environment, while also having security protection. These servers use fixed IP addresses to connect to the Internet.
A domain name is resolved to a certain server and the webpage file is placed on this server, so that the user's computer knows which server to go to to obtain the webpage information of this domain name. This is achieved through a domain name server.
DNS stands for Domain Name Server in English. Each domain name must have at least two DNS servers, so that if one of the DNS servers encounters a problem, the other can also return data about the domain name. There can also be two or more DNS servers, but the DNS records on all of these DNS servers should be the same.
Keep DNS records for the domain name in the DNS server, such as A records and MX records. A record is used to specify the IP address corresponding to the host name (or domain name). MX records the email server used to resolve domain names. In many cases.
When a viewer enters a domain name in the browser address box or clicks on a link from another website to access this domain name, the browser sends a domain name request to the user's internet access provider. The provider's DNS server needs to query the domain name database to see what the DNS server for this domain name is. Then go to the DNS server to retrieve DNS records, that is, to obtain which IP address this domain name points to. After obtaining this IP information, the access provider's server retrieves the webpage content from the server corresponding to this IP address and transmits it to the requesting browser.
This process may seem complicated to describe, but in reality it takes less than one or two seconds to complete.
