HOSTS(5)						      BSD File Formats Manual							  HOSTS(5)

NAME

     hosts -- host name data base

DESCRIPTION

     The hosts file contains information regarding the known hosts on the network.  It can be used in conjunction with the DNS, and the NIS maps
     'hosts.byaddr', and 'hosts.byname', as controlled by nsswitch.conf(5).

     For each host a single line should be present with the following information:
	   address hostname [alias ...]

     These are:
	   address   Internet address
	   hostname  Official host name
	   alias     Alias host name

     Items are separated by any number of blanks and/or tab characters.  A hash sign (``#'') indicates the beginning of a comment; characters up
     to the end of the line are not interpreted by routines which search the file.

     When using the name server named(8), or ypserv(8), this file provides a backup when the name server is not running.  For the name server, it
     is suggested that only a few addresses be included in this file.  These include address for the local interfaces that ifconfig(8) needs at
     boot time and a few machines on the local network.

     This file may be created from the official host data base maintained at the Network Information Control Center (NIC), though local changes
     may be required to bring it up to date regarding unofficial aliases and/or unknown hosts.	As the data base maintained at NIC is incomplete,
     use of the name server is recommended for sites on the DARPA Internet.

     As network addresses, both IPv4 and IPv6 addresses are allowed.  IPv4 addresses are specified in the conventional dot (``.'') notation using
     the inet_pton(3) routine from the Internet address manipulation library, inet(3).	IPv6 addresses are specified in the standard hex-and-colon
     notation.	Host names may contain any printable character other than a field delimiter, newline, or comment character.

FILES

     /etc/hosts  The hosts file resides in /etc.

SEE ALSO

     gethostbyname(3), nsswitch.conf(5), ifconfig(8), named(8)

     Name Server Operations Guide for BIND.

HISTORY

     The hosts file format appeared in 4.2BSD.

BSD
								 November 17, 2000							       BSD