About Name Resolution

In order for people to reach your site on an intranet, you must have a unique IP address that identifies your computer on the network. This address takes the form of a long string of numbers separated by dots (for example, 172.16.255.255). Because a numeric address is difficult for people to remember, text names or "friendly names" are used to provide visitors with an easy-to-remember address, such as www.microsoft.com. Name resolution involves supplying the correct numerical address from the friendly name that was typed into a client browser. This section describes different name resolution systems.

For additional information, see the Windows documentation, accessible by clicking Help on the Start menu.

Intranet Name Resolution Systems

An intranet is a private local area network (LAN) that uses Internet technology. To receive and deliver information packets successfully, each computer's IP address must be successfully mapped to its text name. The names and addresses can be assigned by using any of several different name-to-address resolution systems. You should make your choice based on the size of your intranet, how often computers are added or moved, and the software installed on Microsoft® Windows 2000® Server. The following sections describe how computers on intranets receive their names and addresses.

IP Address Assignment

IP addresses can be assigned in two ways: static or dynamic. Your network can use just one, or a mixture of both.

Static The system administrator assigns and tracks IP addresses for each computer on the intranet. Static assignment works best on small, infrequently changing networks.
Dynamic A Dynamic Host Configuration Protocol (DHCP) server temporarily leases an IP address to a client when the client logs on to the network. When a client logs on, the DHCP server assigns an IP address from its pool of currently available addresses. As the end of the lease approaches, the client computer negotiates with the server to renew the lease if necessary. When the client logs off, the address is released again and can be reassigned to a new client. A DHCP server relieves the system administrator of the burden of tracking IP address assignment and is particularly useful on large or frequently changing networks. A DHCP server permits only one IP address to be assigned to each computer on the network.

Note If you want to assign multiple IP addresses to one network card, then you must use a static address assignment for that computer.

Name Resolution Systems

Windows networking components rely on the NetBIOS naming convention. In contrast, TCP/IP components rely on a naming convention known as the Domain Name System (DNS). Under Windows, the DNS host name defaults to the same name as the NetBIOS computer name. The mapping of computer names to IP addresses can be done in two ways:

Static The system administrator creates a text file, called a HOSTS file (for DNS names), or an LMHOSTS file (for NetBIOS names), and enters each computer's name and IP address. The file is then distributed on the network. When a request for a connection to another computer is made, the file is used to resolve the name to the correct IP address. This system works well for simple networks that change infrequently.
Dynamic When a client computer logs on, a DHCP server assigns an address and sends the IP address assignment to a Windows Internet Name Service (WINS) server. The WINS server registers the computer's name, and when a request is made for a NetBIOS computer name, the WINS server resolves the name to the correct IP address. This automatic recognition and mapping of computer names and addresses eases the administrative burden of large or frequently changing networks.

DNS names are typically resolved using static information. The DNS server contains a portion of the static database listing host names and addresses. If the requested name is not in the DNS server's portion of the database, it sends a query to other DNS servers to get the requested information. The DNS server that runs on Windows can be configured to query a WINS server for name resolution of the lower levels of the DNS hierarchical naming structure. Because WINS assigns computer names dynamically, this effectively changes DNS from a static system to a dynamic system.

If you are setting up multiple Web or FTP sites on a single server, each with its own IP address, you might encounter problems with automatic DNS registration. To ensure correct IP binding and DNS registration, disable Windows 2000 Server automatic DNS registration and manually configure DNS registration for the sites. For more information about disabling automatic DNS registration and manually configuring DNS registration, see the Windows 2000 Server documentation.