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一、什么是DNS 在Internet上有千百万台主机,为了区分这些主机,人们给每台主机都分配了一个专门的地址,称为IP地址。通过IP地址就可以访问到每一台主机。IP地址由4部分数字组成,各部分之间用小数点分开。在你的浏览器上打入这个IP地址,就可以访问到所对应的网站。虽然可以通过IP地址来访问每一台主机,但是要记住那么多枯燥的数字串显然是非常困难的。就象在日常生活中,我们通常会去记地名,而非地址。当你跳上一辆出租车时,你会对司机说“电报大楼”,而不会跟司机说“长安街X号”。出租车司机会把电报大楼转换成路名,最后把你送到那里去。同样的,你在因特网上游荡时,当你输入一个网址时,网络上会有一台机器负责帮你把网址转换成所对应的IP,这种服务就叫做DNS(Domain NamingSystem),负责处理DNS工作的机器,称为DNSServer,或者称DNS服务器。域名由若干部分组成,各部分之间用小数点分开。例如“首都在线”主机的域名就是“www.263.com.cn”,显然域名比IP地址好记忆多了。
First, what is the DNS There are millions of hosts on the Internet, in order to distinguish between these hosts, people are assigned to each host a special address, called the IP address. Through the IP address can access to each host. The IP address consists of four numbers, separated by decimal points. In your browser into this IP address, you can visit the corresponding website. Although each host can be accessed by IP address, it is obviously very difficult to remember so many boring numbers. Just as in everyday life, we usually remember names, not addresses. When you hop on a taxi, you say “telegraph building” to the driver instead of saying “Chang An Avenue X” to the driver. The taxi driver will convert the telegraph building into a road name, and finally send you there. Similarly, when you wander the Internet, when you type in a web address, there is a machine on the network that will help you to translate the web address into the corresponding IP. This service, called the Domain Naming System (DNS), handles DNS work The machine, called DNSServer, or DNS server. The domain name consists of several parts separated by decimal points. For example, “Capital Online” host domain name is “www.263.com.cn”, Obviously the domain name memory better than the IP address.