IPcalc - uma bela ferramenta de redes

$ ipcalc 192.168.1.2
Address: 192.168.1.2 11000000.10101000.00000001. 00000010
Netmask: 255.255.255.0 = 24 11111111.11111111.11111111. 00000000
Wildcard: 0.0.0.255 00000000.00000000.00000000. 11111111
=>
Network: 192.168.1.0/24 11000000.10101000.00000001. 00000000
HostMin: 192.168.1.1 11000000.10101000.00000001. 00000001
HostMax: 192.168.1.254 11000000.10101000.00000001. 11111110
Broadcast: 192.168.1.255 11000000.10101000.00000001. 11111111
Hosts/Net: 254 Class C, Private Internet

ipcalc takes an IP address and netmask and calculates the resulting broadcast,
network, Cisco wildcard mask, and host range. By giving a second netmask, you
can design subnets and supernets. It is also intended to be a teaching tool
and presents the subnetting results as easy-to-understand binary values.

Enter your netmask(s) in CIDR notation (/25) or dotted decimals (255.255.255.0).
Inverse netmasks are recognized.
If you omit the netmask ipcalc uses the default netmask for the class of your network.

No seu site, também existe a funcionar como ferramenta online.

Para utilizadores como eu de Debian e Debian based, como o Sidux, Ubuntu e derivados, está a um $sudo aptitude install ipcalc

Nota: em Sidux não se deve usar o aptitude mas sim o apt-get