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NETMASK(1)			 Debian	Linux			    NETMASK(1)

NAME
       netmask - a netmask generation and conversion program

SYNOPSIS
       netmask [ options ] spec	[ spec ... ]

DESCRIPTION
       This  program  accepts and produces a variety of	common network address
       and netmask formats.  Not only can it convert address and netmask nota-
       tions,  but it will optimize the	masks to generate the smallest list of
       rules.  This is very handy if you've  ever  configured  a  firewall  or
       router  and  some  nasty	 network administrator before you decided that
       base 10 numbers were good places	to start and end groups	of machines.

OPTIONS
       -h, --help
	      Print a summary of the options

       -v, --version
	      Print the	version	number

       -d, --debug
	      Print status/progress information

       -s, --standard
	      Output address/netmask pairs

       -c, --cidr
	      Output CIDR format address lists

       -i, --cisco
	      Output Cisco style address lists

       -r, --range
	      Output ip	address	ranges

       -x, --hex
	      Output address/netmask pairs in hex

       -o, --octal
	      Output address/netmask pairs in octal

       -b, --binary
	      Output address/netmask pairs in binary

       -n, --nodns
	      Disable DNS lookups for addresses

DEFINITIONS
       A spec is an address specification, it can look like:

       address
	      One address.

       address1:address2
	      All addresses from address1 to address2.

       address1:+address2
	      All addresses from address1 to address1+address2.

       address/mask
	      A	group starting at address spanning mask.

       An address is an	internet network address, it can look like:

       ftp.gnu.org
	      An internet hostname.

       209.81.8.252
	      A	standard dotted	quad internet address notation.

       100    A	decimal	number (100 in this case).

       0100   An octal number preceded by "0" (64 in this case).

       0x100  A	hexadecimal number preceded by "0x" (256 in this case).

       A mask is a network mask, it can	look like:

       255.255.224.0
	      A	dotted quad netmask (netmask will complain  if	it  is	not  a
	      valid netmask).

       0.0.31.255
	      A	 Cisco	style inverse netmask (preceded	by a tilde (~) charac-
	      ter).

       8      The number of bits set to	one from the left (CIDR	notation).

       010    The number of bits set to	one from the left in octal.

       0x10   The number of bits set to	one from the left in hexadecimal.

AUTHOR
       netmask was written by Robert Stone.  Some algorithm design  and	 opti-
       mization	 was  provided	by  Tom	Lear.  This manual page	was written by
       Robert Stone.

BUGS
       Let me know if you find any.  This man page is a	 bit  more  simplistic
       than I'd	like, but I've forgotten most of the groff I once knew.

SEE ALSO
       ipchains(1),  ipfwadm(8),  netstat(8),  route(8),  routed(8), gated(8),
       tcpd(8)

Debian Project			  15 May 1999			    NETMASK(1)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | DEFINITIONS | AUTHOR | BUGS | SEE ALSO

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