netmask.texi

\input texinfo @c -*-texinfo-*-
@c %**start of header
@setfilename netmask.info
@settitle Generating Optimized Network Masks
@finalout
@setchapternewpage odd
@c %**end of header

@dircategory General Commands
@include version.texi
%@set EDITION 2.02
%@set VERSION 2.2
%@set UPDATED 26 May 1999

@ifinfo
This file documents the @code{netmask} command for generating terse
network masks.

Manual adapted from GNU Hello Manual

Adaptation Copyright (c) 1999 Robert Stone

GNU Hello Manual Copyright (C) 1992, 1993 Free Software Foundation, Inc.

Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
are preserved on all copies.

@ignore
Permission is granted to process this file through TeX and print the
results, provided the printed document carries copying permission
notice identical to this one except for the removal of this paragraph
(this paragraph not being relevant to the printed manual).

@end ignore
Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the entire
resulting derived work is distributed under the terms of a permission
notice identical to this one.

Permission is granted to copy and distribute translations of this manual
into another language, under the above conditions for modified versions,
except that this permission notice may be stated in a translation approved
by the Foundation.
@end ifinfo

@titlepage
@title Mask
@subtitle The Network Mask Generation Program
@subtitle Edition @value{EDITION}, for Hello Version @value{VERSION}
@subtitle @value{UPDATED}
@author by Robert Stone

@page
@vskip 0pt plus 1filll
Manual adapted from GNU Hello Manual

Adaptation Copyright (c) 1999 Robert Stone

GNU Hello Manual Copyright @copyright{} 1992, 1993 Free Software Foundation,
Inc.

Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
are preserved on all copies.

Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the entire
resulting derived work is distributed under the terms of a permission
notice identical to this one.

Permission is granted to copy and distribute translations of this manual
into another language, under the above conditions for modified versions,
except that this permission notice may be stated in a translation approved
by the Foundation.
@end titlepage

@node Top, , , (dir)

@ifinfo
This file documents the @code{netmask} command for generating terse
network masks.
@end ifinfo

@menu
* Instructions::	How to read this manual. 
* Copying::		How you can copy and share @code{netmask}.
* Overview::		Preliminary information.
* Sample::		Sample output from @code{netmask}.
* Invoking netmask::	How to run @code{netmask}.
* Problems::		Reporting bugs.
* Concept Index::	Index of concepts.
@end menu

@node Instructions, Copying, , Top
@chapter How to Read This Manual

@cindex reading
@cindex manual, how to read
@cindex how to read
To read this manual, begin at the beginning, reading from left to right
and top to bottom, until you get to the end.  Then stop.  You may pause
for a beer anywhere in the middle as well, if you wish.  (Please note,
however, that The King strongly advises against heavy use of
prescription pharmaceuticals, based on his extensive personal and
professional experience.)

@node Copying, Overview, Instructions, Top
@include gpl.texi

@node Overview, Sample, Copying, Top
@chapter Overview
@cindex overview

The `netmask' program accepts and produces a variety of common network
address and netmask formats.  Not only can it convert address and
netmask notations, 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.  Since I often have trouble even describing the process of
generating optimal netmasks to fledgling network administrators, this
seemed like a much better solution.

I originally had a 32 line perl script to do this using nested for
loops, but I found it too slow to deal with real internet addresses, so
it only worked well with the last 8 bits.  It couldn't merge ranges at
all and it also only reported in one format... network address in
decimal and the binary negation of the netmask plus one.

Today netmask is written in C, and instead of for loops it does a slew
of bit manipulation.  It also accepts and reports common formats
including CIDR, regular address and netmask pairs and Cisco style masks.

It allows those netadmins who don't count on their hands in binary
to come up with efficient firewalling and routing rules which would
otherwise be unavailable to them making their router config files
cluttered and their firewalls inefficient.  Because it is protected by
the GNU General Public License, users are free to share and change it.

@code{netmask} was written by Robert Stone.  Some algorithm design and
optimization was provided by Tom Lear.

@node Sample, Invoking netmask, Overview, Top
@chapter Sample Output
@cindex sample

Here are some realistic examples of running @code{netmask}.

This is the output of the command @samp{netmask 10.0.0.0,10.0.0.25}:

@example
       10.0.0.0/28
       10.0.0.16/29
       10.0.0.24/31
@end example

This is the output of the command
@samp{netmask 10.1.0.0/16 10.2.0.0/16 10.3.0.0/16}:

@example
       10.1.0.0/16
       10.2.0.0/15
@end example

This is the output of the command
@samp{netmask --standard 10.0.0.0,+24}:

@example
       10.0.0.0/255.255.255.240
      10.0.0.16/255.255.255.248
      10.0.0.24/255.255.255.255
@end example

@node Invoking netmask, Problems, Sample, Top
@chapter Invoking @code{netmask}
@cindex invoking
@cindex version
@cindex options
@cindex usage
@cindex help
@cindex getting help

The format for running the @code{netmask} program is:

@example
netmask @var{option} @var{spec} [@var{spec} @dots{}]
@end example

A @var{spec} is an address specification, it can look like:
@cindex spec
@table @samp
@item @var{address}
One address.
@item @var{address1},@var{address2}
All addresses from @var{address1} to @var{address2}.
@item @var{address1},+@var{address2}
All addresses from @var{address1} to @var{address1} + @var{address2}.
@item @var{address}/@var{mask}
A group starting at @var{address} spanning @var{mask}
@end table

An @var{address} is an internet network address, it can look like:
@cindex address
@table @samp
@item ftp.gnu.org
An internet hostname.
@item 209.81.8.252
A standard dotted quad internet address notation.
@item 2001:0db8:0000:0000:0000:ff00:0042:8329
An RFC5952 IPv6 internet address.
@item 100
A decimal number (100 in this case).
@item 0100
An octal number preceded by "0" (64 in this case).
@item 0x100
A hexadecimal number preceded by "0x" (256 in this case).
@end table

A @var{mask} is a network mask, it can look like:
@cindex mask
@table @samp
@item 255.255.224.0
A dotted quad netmask (@code{netmask} will complain if it is not a valid
netmask)
@item 0.0.31.255
A Cisco style inverse netmask (with the same checks).
@item ffff:ffff::
An RFC5952 IPv6 internet address.  (with the same checks)
@item 8
CIDR notation (The number of bits set to one from the left).
@item 010
Octal CIDR.
@item 0x10
hexadecimal CIDR.
@end table

@code{netmask} supports the following options:

@table @samp
@item --help
@itemx -h
Print an informative help message describing the options and then exit.

@item --version
@itemx -v
Print the version number of @code{netmask} on the standard error output
and then exit.

@item --debug
@itemx -d
@cindex debug
Print status or progress information on stderr.  Probably only useful to
the author and subject to change at will.

@item --standard
@itemx -s
@cindex standard
Formats output as standard address and netmask pairs, such as:
@example
     10.1.8.128/255.255.255.224
@end example

@item --cidr
@itemx -c
@cindex cidr
@cindex CIDR
Formats output in CIDR notation, such as:
@example
     10.1.8.128/27
@end example

@item --cisco
@itemx -i
@cindex cisco
Formats output in the style accepted by Cisco 2500 series router
config files, such as:
@example
     10.1.8.128 0.0.0.31
@end example

@item --range
@itemx -r
@cindex range
Formats output as a set of ranges and the number of addresses
contained in them, such as:
@example
     10.1.8.128-10.1.8.159      (32)
@end example

@item --hex
@itemx -x
@cindex hexadecimal
Formats output as hexadecimal address and netmask pairs, such as:
@example
0x0a010880/0xffffffe0
@end example

@item --octal
@itemx -o
@cindex octal
Formats output as octal addresses and netmask pairs, such as:
@example
01200204200/037777777740
@end example

@item --binary
@itemx -b
@cindex binary
Formats output as binary addresses and netmask pairs, such as:
@example
00001010 00000001 00001000 10000000 / 11111111 11111111 11111111 11100000
@end example

@item --nodns
@itemx -n
@cindex DNS
Disables dns lookups on input addresses.

@item --files
@itemx -f
@cindex files
Treat arguments as input files.
@end table

@node Problems, Concept Index, Invoking netmask, Top
@chapter Reporting Bugs
@cindex bugs
@cindex problems

If you find a bug in @code{netmask}, please send electronic mail
to @w{@samp{netmask-bug@@trap.mtview.ca.us}}.  Include the version
number, which you can find by running @w{@samp{netmask --version}}.  Also
include in your message the output that the program produced and the
output you expected.@refill

If you have other questions, comments or suggestions about
@code{netmask}, contact Talby via electronic mail to
@w{@samp{talby@@trap.mtview.ca.us}}.  Talby will try to help you out,
although he may not have the resources to fix your problems.

@node Concept Index, , Problems, Top
@unnumbered Concept Index

@cindex tail recursion
@printindex cp

@shortcontents
@contents
@bye