An IP address is used to identify a node (such as a workstation, a server, or a printer) on any network (such as your intranet or the Internet) and to specify routing information from one network or subnet to another network or subnet. Each node on a network or subnet must be assigned a unique IP address.
For Dial-Up Networking clients, the RAS server can automatically assign IP addresses to remote workstations when they connect. The IP address is obtained from a static pool that has been reserved for use by the RAS server, or through dynamic allocation from a Dynamic Host Configuration Protocol (DHCP) server. (For more information about DHCP, see the next section.)
Where needed, the RAS server can be configured to allow remote clients to specify their own IP addresses. This is useful for remote workstations that each need to be guaranteed a specific IP address when they are connected to the network.
Subnet masks are used in conjunction with the IP address to create subnets within an IP address space. Subnet masks are usually provided by the TCP/IP network administrator, such as an Internet service provider. If you need more information about subnet masks, see the Windows NT Server Networking Supplement.