How can I determine if an organization is using NAT?

As far as I understand, I can tell if an organisation is using NAT if they are using private IP address space.

It can be determined that an organization is us开发者_如何学Cing private IP address space if its addresses fall into the following ranges, reserved for private uses by Internet standards groups:

• 10.0.0.0 through 10.255.255.255
• 169.254.0.0 through 169.254.255.255 (APIPA only)
• 172.16.0.0 through 172.31.255.255
• 192.168.0.0 through 192.168.255.255

Am I correct.....? Please correct the logic if it is not correct.

While you are basically correct about which space is considered "private" (see RFC 1918 section 3), I do not think you can make this assumption in your program, for the following reasons:

• An organization might be using private addresses, but not be using NAT at all (for example, a completely private intranet)
• An organization might be using NAT, but with a reserved public subnet. (Yes, I have seen organizations with IP address space to burn do this.)

Your question is practically incomprehensible, but taking this from the title:

How will i get to know if organisation is using NAT?

You can't.