Host name resolution

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

Host name resolution

Host name resolution means successfully mapping a host name to an IP address. A host name is an alias that is assigned to an IP node to identify it as a TCP/IP host. The host name can be up to 255 characters long and can contain alphabetic and numeric characters, hyphens, and periods. You can assign multiple host names to the same host.

Windows Sockets (Winsock) programs, such as Internet Explorer and the FTP utility, can use one of two values for the destination to which you want to connect: the IP address or a host name. When the IP address is specified, name resolution is not needed. When a host name is specified, the host name must be resolved to an IP address before IP-based communication with the desired resource can begin.

Host names can take various forms. The two most common forms are a nickname and a domain name. A nickname is an alias to an IP address that individual people can assign and use. A domain name is a structured name in a hierarchical namespace called the Domain Name System (DNS). An example of a domain name is www.microsoft.com.

Nicknames are resolved through entries in the Hosts file, which is stored in the systemroot\System32\Drivers\Etc folder. For more information, see TCP/IP database files.

Domain names are resolved by sending DNS name queries to a configured DNS server. The DNS server is a computer that stores domain name-to-IP address mapping records or has knowledge of other DNS servers. The DNS server resolves the queried domain name to an IP address and sends the result back.

You are required to configure your computers with the IP address of your DNS server in order to resolve domain names. You must configure Active Directory-based computers running Windows XP Professional or Windows Server 2003 operating systems with the IP address of a DNS server.

For more information, see DNS defined.