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networks(4)                      File Formats                      networks(4)

       networks - network name database



       The  networks  file is a local source of information regarding the net-
       works which comprise the Internet. The networks  file can  be  used  in
       conjunction  with, or instead of, other networks sources, including the
       NIS maps  networks.byname and  networks.byaddr and the NIS+ table  net-
       works.  Programs  use the getnetbyname(3SOCKET) routines to access this

       The network file has a single line for each network, with the following

       official-network-name network-number aliases

       Items  are  separated  by any number of  SPACE 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. This file
       is normally created from the official network  database  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 networks.

       Network numbers may be specified in the conventional dot (`.') notation
       using the inet_network routine from the Internet  address  manipulation
       library,  inet(7P).  Network  names may contain any printable character
       other than a field delimiter, NEWLINE, or comment character.

       getnetbyaddr(3SOCKET),   getnetbyname(3SOCKET),   inet(3SOCKET),   nss-
       witch.conf(4), inet(7P)

       The  official SVR4 name of the networks file is /etc/inet/networks. The
       symbolic link /etc/networks exists for BSD compatibility.

       The network number in networks database is the host address shifted  to
       the right by the number of 0 bits in the address mask. For example, for
       the address that has a mask of fffffe00, its network  num-
       ber is 803351.  This is obtained when the address is shifted right by 9
       bits. The address maps to 12.66.23. The trailing 0 bits should  not  be
       specified.  The network number here is different from that described in
       netmasks(4).  For  this  example,  the  entry  in  netmasks  would   be     fffffe00.

SunOS 5.10                        17 Jan 2002                      networks(4)