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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 5.9			  17 Jan 2002			   networks(4)


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