subnetcalc — IPv4/IPv6 Subnet Calculator

       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 and FreeBSD, /dev/urandom is
               used for random number generation.

       -uniquelocalhq
               Like -uniquelocal, but using /dev/random instead on Linux and FreeBSD 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 delivering random
               input e.g. by pressing keys or moving the mouse.

       -nocolour | -nocolor
               Turns colourised output off.

       -v | -version
               Just prints program version.

       Thomas Dreibholz
       https://www.nntb.no/~dreibh/subnetcalc
       mailto://thomas.dreibholz@gmail.com

subnetcalc                                      January 06, 2025                                   subnetcalc(1)

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 understandability. Furthermore, it
       prints useful information on specific address types (e.g. type, scope, interface ID, etc.).

       subnetcalc -v

       subnetcalc 132.252.250.0 255.255.255.0

       subnetcalc 132.252.250.0/255.255.255.0 -nocolor

       subnetcalc 132.252.250.0 24

       subnetcalc 132.252.250.0/24 -nocolour

       subnetcalc fe80::2f0b:a04e:15c2:bc68 64

       subnetcalc fe80::2f0b:a04e:15c2:bc68%wlp4s0 64

       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 düsseldorf.de 28

       subnetcalc www.köln.de

       subnetcalc räksmörgås.josefsson.org 24

       subnetcalc — IPv4/IPv6 Subnet Calculator

subnetcalc  [Address  |  Address  Prefix  |  Address  Netmask  |  Address/Prefix  | Address/Netmask] [-n]
                  [-uniquelocal] [-uniquelocalhq] [-nocolour | -nocolor] [-v | -version]