Your IP address:
Provider:
...

For example: 3.143.17.127

/
Input
Address: 204.123.0.0
Netmask: 255.255.0.0 = 16
Inversion mask: 0.0.255.255
Binary: 11001100.01111011.00000000.00000000
Reserved: No
Result
Network: 204.123.0.0/16 (Class C)
First IP: 204.123.0.1
Last IP: 204.123.255.254
Broadcast: 204.123.255.255
Network range: 204.123.0.0 - 204.123.255.255
List of all IP addresses: 204_123_0_0-16.txt
Number of hosts: 65534
Number of IP addresses: 65536