NAME
    addrtool - perform IP address/CIDR/netmask calculations

SYNOPSIS
    addrtool /b
        show the netmask for the specified CIDR block

    addrtool m.m.m.m
        show the CIDR block for the specified netmask

    addrtool a.a.a.a/b
    addrtool a.a.a.a m.m.m.m
        for the specified address, show the corresponding network and
        broadcast addresses, the first and last possible host addresses, and
        the number of available host addresses

    addrtool a.a.a.a/b /b
    addrtool a.a.a.a/b m.m.m.m
    addrtool a.a.a.a m.m.m.m /b
    addrtool a.a.a.a m.m.m.m m.m.m.m
        for the specified network (or address), show the network, broadcast,
        first host, and last host addresses for all subnets specified by the
        second netmask of CIDR block

    addrtool --help
    addrtool --man
        this man page

DESCRIPTION
    addrtool performs simple calculations related to IP addresses, subnet
    masks, and CIDR blocks. It can convert between netmasks and CIDR-style
    */b* notations, show the network and broadcast addresses for a specific
    IP address, and split a network into subnets.

    In the SYNOPSIS, *a.a.a.a* is an IP address, *a.a.a.a/b* is an IP
    address with its CIDR block, */b* is a CIDR block, and *m.m.m.m* is a
    subnet mask.

EXIT STATUS
    addrtool returns 0 on success, 1 for invalid input, and 2 for certain
    internal errors

AUTHOR
    Adam Moskowitz, <adamm@menlo.com>