hosts(4)                                                    hosts(4)


       NAME
             hosts - host name data base

       SYNOPSIS
             /etc/hosts

       DESCRIPTION
             The hosts file associates IP addresses with host names.  At
             sites that do not run the Domain Name Service (DNS), the hosts
             file is normally created from the official Internet host data
             base maintained at the Network Information Control Center
             (NIC) [see gettable(1M) and htable(1M)].  When the NIC data
             base is used to build the hosts file, local changes may be
             required to bring it up to date regarding unofficial aliases
             and/or unknown hosts.  At sites that run DNS, the hosts file
             typically contains name and address information about
             important hosts on the local network only.

          Files
             /var/yp/domainname/hosts.byaddr    Corresponding NIS map
                                                containing host names and
                                                IP addresses.  The IP
                                                address is the key in the
                                                map.
             /var/yp/domainname/hosts.byname    Same as hosts.byaddr,
                                                except key is host name
                                                instead of IP address.

       USAGE
             For each host's interface, the hosts file contains a single
             line with the following information:

                   host-IP-address  host-name  aliases

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

             Host IP addresses are specified in the conventional `.'
             notation using the inet_addr routine from the Internet address
             manipulation library, inet(3N).  Host names and aliases may
             contain any printable character other than a field delimiter,
             NEWLINE or comment character.




                           Copyright 1994 Novell, Inc.               Page 1

      hosts(4)                                                    hosts(4)


            Note that if you change a IP address, or add a new one to this
            file, you must run the script listen.setup, as follows:

                  sh /etc/inet/listen.setup

            to update the port monitors with the new IP address.

            When the Network Information Service (NIS) is in use, it
            references the NIS maps hosts.byaddr or hosts.byname on the
            NIS server instead of /etc/hosts.  However, at boot time, the
            NIS maps are not used; /etc/hosts is consulted instead.

         Examples
            Here is a typical line from the hosts file:

                  192.9.1.20  gaia  mailhost    # John Smith

      REFERENCES
            gethostent(3N), gettable(1M), htable(1M), inet(3N), netdir(3N)





























                          Copyright 1994 Novell, Inc.               Page 2