How to find SUB-NET for a defined IP Group.?

Question

I need to find out how an IP group is divided between subnets inside the network.

For example, I have an IP range 192.168.0.0 - 192.168.255.255 and I have to guess how it's divided inside. Maybe they are divided in /23 or /24 or few of them are /22 .

I was trying different ways by using Nmap and netaddr library from python. But so far it seems impossible to get the information.

Answer 1

There's no way to detect that from the outside. You can subnet a /16 prefix into /17, /18, /19, ...., /30, or /31 subnets any which way.

Check out this excellent Q&A for how subnetting works.