/usr/bin/ipcalc

IP Calculator 0.51

Enter your netmask(s) in CIDR notation (/25) or dotted decimals
(255.255.255.0). Inverse netmask are recognized. If you omit the
netmask, ipcalc uses the default netmask for the class of your
network.

Look at the space between the bits of the addresses: The bits before
it are the network part of the address, the bits after it are the host
part. You can see two simple facts: In a network address all host bits
are zero, in a broadcast address they are all set.

The class of your network is determined by its first bits.

If your network is a private internet according to RFC 1918 this is
remarked. When displaying subnets the new bits in the network part of
the netmask are marked in a different color.

The wildcard is the inverse netmask as used for access control lists
in Cisco routers. You can also enter netmasks in wildcard notation.

Do you want to split your network into subnets? Enter the address and
netmask of your original network and play with the second netmask
until the result matches your needs.

Questions? Comments? Drop me a mail: krischan at jodies.de
http://jodies.de/ipcalc

Thanks for your nice ideas and help to make this tool more useful:

Bartosz Fenski
Denis A. Hainsworth
Foxfair Hu
Frank Quotschalla
Hermann J. Beckers
Igor Zozulya
Kevin Ivory
Lars Mueller
Lutz Pressler
Oliver Seufer
Scott Davis
Steve Kent
Sven Anderson
Torgen Foertsch
Edward
Nick Clifford
Victor Engmark

Usage: ipcalc [options] <ADDRESS>[[/]<NETMASK>] [NETMASK]

ipcalc takes an IP address and netmask and calculates the resulting
broadcast, network, Cisco wildcard mask, and host range. By giving a
second netmask, you can design sub- and supernetworks. It is also
intended to be a teaching tool and presents the results as
easy-to-understand binary values.

 -n --nocolor  Don't display ANSI color codes.
 -c --color    Display ANSI color codes (default).
 -b --nobinary Suppress the bitwise output.
 -c --class    Just print bit-count-mask of given address.
 -h --html     Display results as HTML (not finished in this version).
 -v --version  Print Version.
 -s --split n1 n2 n3
               Split into networks of size n1, n2, n3.
 -r --range    Deaggregate address range.
    --help     Longer help text.

Examples:

ipcalc 192.168.0.1/24
ipcalc 192.168.0.1/255.255.128.0
ipcalc 192.168.0.1 255.255.128.0 255.255.192.0
ipcalc 192.168.0.1 0.0.63.255


ipcalc <ADDRESS1> - <ADDRESS2>  deaggregate address range

ipcalc <ADDRESS>/<NETMASK> --s a b c
                                split network to subnets
				where a b c fits in.

! New HTML support not yet finished.

ipcalc 0.51