What is DNS? The Domain Name System (DNS) is a naming system that translates a website’s URL or name to a numerical IP address. When a person searches for a Domain name, for example www.site123.com, they will type that URL and go to the website.
The computer and Internet Service Provider (ISP) do not know how to find the site by its URL or domain name alone but rather by the IP address associated with that URL. An IP address is a series of numbers associated with the exact physical location of servers associated with the domain name or URL. IP stands for Internet Protocol. Internet Protocol (IP) is the principal communication protocol the internet uses to relay datagrams across networks.
A simplified analogy is to think of Domain Name System as the all-inclusive phone book for the internet. It lists both names and numbers; the name is great, but only by calling the number will you actually reach the person/business.
If it were not for DNS, navigating the internet would be chaos. The DNS is updated rapidly if an IP address or website name changes. In short, the DNS assigns domain names and maps the names to IP addresses. It also designates authoritative name servers for every domain.
Using a client-server model, the Domain Name System operates within a distributed database system. Every domain has at least one Authoritative Domain System name server that publishes information on the domain name servers associated with it and subordinate domains.
There are two types of Authoritative Name Servers: master and slave. The master server stores original or masters of data; the slave server stores copies of the master or original.
The process goes like this. You register a domain name with a domain registry. The registry requires a primary name server and a secondary server.
This is important because if the first or primary server should fail, service can still continue through the secondary name server. Root name servers are at the top of the distributed database hierarchy, the ultimate authority.
从分步指南开始: 1. What is DNS lookup? 2. Domain name registration