Your IP address:
Provider:
...

For example: 3.236.217.172

/
Input
Address: 3.5.120.0
Netmask: 255.255.248.0 = 21
Inversion mask: 0.0.7.255
Binary: 00000011.00000101.01111000.00000000
Reserved: No
Result
Network: 3.5.120.0/21 (Class A)
First IP: 3.5.120.1
Last IP: 3.5.127.254
Broadcast: 3.5.127.255
Network range: 3.5.120.0 - 3.5.127.255
List of all IP addresses: 3_5_120_0-21.txt
Number of hosts: 2046
Number of IP addresses: 2048