subnetcalc(8)						    BSD System Manager's Manual 					     subnetcalc(8)

NAME

     subnetcalc -- IPv4/IPv6 Subnet Calculator

SYNOPSIS

     subnetcalc [Address] [Netmask/Prefix] [-n] [-uniquelocal] [-uniquelocalhq]

DESCRIPTION

     subnetcalc is an IPv4/IPv6 subnet address calculator. For given IPv4 or IPv6 address and netmask or prefix length, it calculates network
     address, broadcast address, maximum number of hosts and host address range. Also, it prints the addresses in binary format for better under-
     standability. Furthermore, it prints useful information on specific address types (e.g. type, scope, interface ID, etc.).

ARGUMENTS

     The following arguments have to be provided:

     Address
	     The IP address. If a hostname is provided here, it is tried to resolve the address by a DNS server and the first returned address is
	     used. Internationalized Domain Names (IDN) are supported.

     Netmask/Prefix
	     The netmask or prefix length (0-32 for IPv4; 0-128 for IPv6).

     -n      Skip trying a reverse DNS lookup.

     -uniquelocal
	     Given an IPv6 address, the first 48 bits of the address are replaced by a randomly chosen IPv6 Unique Local prefix in fc00::/7 (see
	     also RFC 4193). Under Linux, /dev/urandom is used for random number generation.

     -uniquelocalhq
	     Like -uniquelocal, but using /dev/random instead on Linux systems for highest-quality random number generation. On other systems,
	     this option is equal to -uniquelocal. Note, that reading from /dev/random may take some time. You can speed up this process by deliv-
	     ering random input e.g. by pressing keys or moving the mouse.

EXAMPLES

     subnetcalc 132.252.250.0 255.255.255.0

     subnetcalc 132.252.250.0/255.255.255.0

     subnetcalc 132.252.250.0 24

     subnetcalc 132.252.250.0/24

     subnetcalc fec0:2345:6789:1111:221:6aff:fe0b:2674 56

     subnetcalc 2a00:1450:8007::69 64

     subnetcalc ff08::1:2:3

     subnetcalc 131.220.6.5/24

     subnetcalc 132.252.181.87 -n

     subnetcalc www.iem.uni-due.de 24

     subnetcalc www.six.heise.de

     subnetcalc fd00:: 64 -uniquelocal

     subnetcalc fd00::9876:256:7bff:fe1b:3255 56 -uniquelocalhq

     subnetcalc dusseldorf.de 28

     subnetcalc www.koln.de

     subnetcalc raksmorgas.josefsson.org 24

AUTHORS

     Thomas Dreibholz
     http://www.iem.uni-due.de/~dreibh/subnetcalc
     mailto://dreibh@iem.uni-due.de

subnetcalc							   June 19, 2010							subnetcalc