ipcalc
Installation
On ubuntu derivatives, as expected, sudo apt install ipcalc
does the job.
Also available on macos via usual brew
.
Use Examples
Display info on cidr 10.8.0.0/20:
$ ipcalc 10.8.0.0/20
Address: 10.8.0.0 00001010.00001000.0000 0000.00000000
Netmask: 255.255.240.0 = 20 11111111.11111111.1111 0000.00000000
Wildcard: 0.0.15.255 00000000.00000000.0000 1111.11111111
=>
Network: 10.8.0.0/20 00001010.00001000.0000 0000.00000000
HostMin: 10.8.0.1 00001010.00001000.0000 0000.00000001
HostMax: 10.8.15.254 00001010.00001000.0000 1111.11111110
Broadcast: 10.8.15.255 00001010.00001000.0000 1111.11111111
Hosts/Net: 4094 Class A, Private Internet
Split the above cidr into three /24 subnets:
$ ipcalc 10.8.0.0/20 --s 128 128 128
Address: 10.8.0.0 00001010.00001000.0000 0000.00000000
Netmask: 255.255.240.0 = 20 11111111.11111111.1111 0000.00000000
Wildcard: 0.0.15.255 00000000.00000000.0000 1111.11111111
=>
Network: 10.8.0.0/20 00001010.00001000.0000 0000.00000000
HostMin: 10.8.0.1 00001010.00001000.0000 0000.00000001
HostMax: 10.8.15.254 00001010.00001000.0000 1111.11111110
Broadcast: 10.8.15.255 00001010.00001000.0000 1111.11111111
Hosts/Net: 4094 Class A, Private Internet
1. Requested size: 128 hosts
Netmask: 255.255.255.0 = 24 11111111.11111111.11111111. 00000000
Network: 10.8.0.0/24 00001010.00001000.00000000. 00000000
HostMin: 10.8.0.1 00001010.00001000.00000000. 00000001
HostMax: 10.8.0.254 00001010.00001000.00000000. 11111110
Broadcast: 10.8.0.255 00001010.00001000.00000000. 11111111
Hosts/Net: 254 Class A, Private Internet
2. Requested size: 128 hosts
Netmask: 255.255.255.0 = 24 11111111.11111111.11111111. 00000000
Network: 10.8.1.0/24 00001010.00001000.00000001. 00000000
HostMin: 10.8.1.1 00001010.00001000.00000001. 00000001
HostMax: 10.8.1.254 00001010.00001000.00000001. 11111110
Broadcast: 10.8.1.255 00001010.00001000.00000001. 11111111
Hosts/Net: 254 Class A, Private Internet
3. Requested size: 128 hosts
Netmask: 255.255.255.0 = 24 11111111.11111111.11111111. 00000000
Network: 10.8.2.0/24 00001010.00001000.00000010. 00000000
HostMin: 10.8.2.1 00001010.00001000.00000010. 00000001
HostMax: 10.8.2.254 00001010.00001000.00000010. 11111110
Broadcast: 10.8.2.255 00001010.00001000.00000010. 11111111
Hosts/Net: 254 Class A, Private Internet
Needed size: 768 addresses.
Used network: 10.8.0.0/22
Unused:
10.8.3.0/24
10.8.4.0/22
10.8.8.0/21