DNS (Domain Name Server) is a server that converts domain name (domain name) and its corresponding IP address (IP address).
DNS stores a table of domain names and corresponding IP addresses to resolve the domain names of messages. A domain name is the name of a computer or computer group on the Internet. It is used to identify the electronic location (sometimes also the geographical location) of the computer during data transmission.
A domain name consists of a dot-separated string of names, usually including the name of the organization, and always includes a two- to three-letter suffix to indicate the type of organization or the country or region in which the domain is located.
1. Advantages
The reason why domain name resolution does not take a long time is because Internet access providers, such as Beijing Telecom, Henan Telecom, etc., in order to speed up the speed of users opening web pages, usually DNS records for many domain names are cached in their DNS servers.
In this way, when a user of this access provider wants to open a certain web page, the access provider's server does not need to query the domain name database, but directly uses the DNS records in its cache, thereby speeding up the user's access to the website. speed. This is an advantage.
2. Disadvantages
The disadvantage is that the cache of the Internet access provider ISP will be stored for a period of time and will only be updated when needed, and there is no standard for the frequency of updates. . Some ISPs may update once an hour, while others may only update once a day or two.
So newly registered domain names are generally resolved faster. Because all ISPs do not have cache, when users visit, the ISP must query the domain name database to obtain the latest DNS data.
TG：li0947
autoload2021-10-20 09:14:10
Knowledge sharing, sometimes you really have to look at the format. It’s really uncomfortable to read all the words together