1subnetcalc(1)             BSD General Commands Manual            subnetcalc(1)
2

NAME

4     subnetcalc — IPv4/IPv6 Subnet Calculator
5

SYNOPSIS

7     subnetcalc [Address] [Netmask/Prefix] [-n] [-uniquelocal]
8                [-uniquelocalhq] [-nocolour|-nocolor]
9

DESCRIPTION

11     subnetcalc is an IPv4/IPv6 subnet address calculator. For given IPv4 or
12     IPv6 address and netmask or prefix length, it calculates network address,
13     broadcast address, maximum number of hosts and host address range. Also,
14     it prints the addresses in binary format for better understandability.
15     Furthermore, it prints useful information on specific address types (e.g.
16     type, scope, interface ID, etc.).
17

ARGUMENTS

19     The following arguments have to be provided:
20
21     Address
22             The IP address. If a hostname is provided here, it is tried to
23             resolve the address by a DNS server and the first returned ad‐
24             dress is used. Internationalized Domain Names (IDN) are sup‐
25             ported.
26
27     Netmask/Prefix
28             The netmask or prefix length (0-32 for IPv4; 0-128 for IPv6).
29
30     -n      Skip trying a reverse DNS lookup.
31
32     -uniquelocal
33             Given an IPv6 address, the first 48 bits of the address are re‐
34             placed by a randomly chosen IPv6 Unique Local prefix in fc00::/7
35             (see also RFC 4193). Under Linux, /dev/urandom is used for random
36             number generation.
37
38     -uniquelocalhq
39             Like -uniquelocal, but using /dev/random instead on Linux systems
40             for highest-quality random number generation. On other systems,
41             this option is equal to -uniquelocal. Note, that reading from
42             /dev/random may take some time. You can speed up this process by
43             delivering random input e.g. by pressing keys or moving the
44             mouse.
45
46     -nocolour|-nocolor
47             Turns colourised output off.
48

EXAMPLES

50     subnetcalc 132.252.250.0 255.255.255.0
51
52     subnetcalc 132.252.250.0/255.255.255.0 -nocolor
53
54     subnetcalc 132.252.250.0 24
55
56     subnetcalc 132.252.250.0/24 -nocolour
57
58     subnetcalc fec0:2345:6789:1111:221:6aff:fe0b:2674 56
59
60     subnetcalc 2a00:1450:8007::69 64
61
62     subnetcalc ff08::1:2:3
63
64     subnetcalc 131.220.6.5/24
65
66     subnetcalc 132.252.181.87 -n
67
68     subnetcalc www.iem.uni-due.de 24
69
70     subnetcalc www.six.heise.de
71
72     subnetcalc fd00:: 64 -uniquelocal
73
74     subnetcalc fd00::9876:256:7bff:fe1b:3255 56 -uniquelocalhq
75
76     subnetcalc düsseldorf.de 28
77
78     subnetcalc www.köln.de
79
80     subnetcalc räksmörgås.josefsson.org 24
81

AUTHORS

83     Thomas Dreibholz
84     https://www.nntb.no/~dreibh/subnetcalc
85     mailto://thomas.dreibholz@gmail.com
86
87subnetcalc                       July 24, 2014                      subnetcalc
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