ARPA Host Name Server Protocol

The ARPA Host Name Server Protocol (NAMESERVER)^[1] is an obsolete network protocol used in translating a host name to an Internet address. IANA Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) port 42 for NAMESERVER; this port is more commonly used by the Windows Internet Name Service (WINS) on Microsoft operating systems.

The NAMESERVER protocol is used by the DARPA Trivial Name Server, a server process called tnamed that is provided in some implementations of UNIX.^[2][3][4]

Support for the NAMESERVER protocol has been deprecated, and may not be available in the latest implementations of all UNIX operating systems.^[5] The Domain Name System (DNS) has replaced the ARPA Host Name Server Protocol and the DARPA Trivial Name Server.

• List of TCP and UDP port numbers
• List of Unix operating systems

• IEN 116 Internet Name Server
• Development of the domain name system