Giả định cho Network Setup mạng TCP / IP cũng có thể được chia cho các địa chỉ IP công cộng và tư nhân: • công cộng địa chỉ IP của bạn là được giao cho bạn bởi nhà cung cấp dịch vụ Internet (ISP). Trong thực tế, địa chỉ IP này được phân bổ cho các ISP quan Internet Assigned Numbers (IANA - ) | Assumptions for Network Setup The TCP IP networks can also be divided by public and private IP addresses Your public IP address is assigned to you by your Internet service provider ISP . In fact this IP address is allocated to the ISP by the Internet Assigned Numbers Authority IANA -http . It s your public IP address that identifies you on the Internet. Private IP addresses are those like the addresses used in the diagram above that identify a device within a private or non-Internet connected network. There are three TCP IP network address ranges reserved for use in private networks and . A netmask is a 32-bit string that hides the network part of an IP address so that only the host computer part of the address remains. For example the netmask looks like an IP address but in fact hides the first 24 bits of the IP address so that only the last 8 bits remain recall that 255 is the decimal representation of the binary 11111111 . Hence the netmask is commonly used for Class C IP addresses to reveal the specific host computer address publicly. There are a few more definitions that will be useful here A gateway is a host that is connected to two or more physical networks and hence allows messages to switch between them. The term hostname refers to the unique name of the machine so that it can identify itself on the network. Finally the domain name system or DNS is a distributed database that translates domain names into IP addresses and vice versa. For example DNS translates the domain name to the IP address . With all that in mind let s return to those two machines on our network - the Red Hat Linux 9 server machine and the Windows 2000 client laptop machine. Here are the network configuration settings we used for those two machines in this chapter. The Red Hat Linux 9 server machine is set up as a firewall and router and .