`ipcalc` - simple IP network calculator

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

Options you will use

-b, --nobinary: suppress the bitwise output
NETMASK (second argument): split the network into subnets of this size

Examples

$ ipcalc 10.0.0.0/26

network, broadcast, host range and host count of a /26

$ ipcalc 10.0.0.0/22 26

every /26 inside the /22

Gotchas

Hosts/Net is 2^(32-prefix) - 2. Azure takes three more per subnet: the first four and the last address are reserved.
Learn to do this in your head; use ipcalc as the answer key.

Taught in

Try ipcalc in a real terminal Free, in your browser - a real Ubuntu terminal to try it in, with missions that check your work.