Internet address and router device on a tcP/IP network the format of an ter or IP Address(P地址): An identifier for a compi address is a 32-bit numeric address written as four numbers separated by periods. Each number can be zero to 255. For example, 204.. 130 Router(路由器): Device which checks the ip address of the data at every intersection on the back bone that carries the ip address of its destination
IP Address （IP地址）: An identifier for a computer or device on a TCP/IP network. The format of an IP address is a 32-bit numeric address written as four numbers separated by periods. Each number can be zero to 255. For example, 204.194.30.130 Router （路由器）: Device which checks the IP address of the data at every intersection on the back bone, that carries the IP address of its destination . 22
Domain Name People find it difficult to remember long strings of umbers, so host computers also have names called domain names Domain name -"fully qualified domain name (FQDN), usually typed in all lowercase Key component of URLs and e-mail addresses www.msuedw/biologycatalog.htm-www.msueduisthe domain name
People find it difficult to remember long strings of numbers, so host computers also have names called domain names Domain name – “fully qualified domain name” (FQDN), usually typed in all lowercase ◦ Key component of URLs and e-mail addresses ◦ www. msu.edu/biologycatalog.htm - www.msu.edu is the domain name 23
Domain names域名 ped in lowercase Ends with three letter extension which is its top-level domain Top-level domain Domain Description com Commercial businesses edu Four-year colleges and universities gov U.S. government agencies Organizations established by international treaties m U.S. military organizations net Internet administrative organizations org Professional and nonprofit organizations
Typed in lowercase Ends with three letter extension which is its top-level domain Top-level domain 24
Domain Name space域名空间 地理顶级域名 类别顶级域名 apa du org ac u (Microdot. com com. cn edu. cn scu. edu.cn officeMicrodoft.com)(indow.microdoft.com sina. com. cn
25 类别顶级域名 地理顶级域名
Domain Name System Each name corresponds to an IP address FIGURE 5-19 Domain name A domain name request Domain name system som to name sever w travelocity. com Huge database that womne d otarshese e ondine an then be attached to houses the names and requests for web pages 151193.165.126 IP addresses www.travelocity.com s Domain name servers Computers that house the database
Each name corresponds to an IP address Domain name system – Huge database that houses the names and IP addresses Domain name servers – Computers that house the database 26