I'm having some problems finding the external IP Address of a doctors surgery in the NHS Network called N3.
You see N3 is a giant private network across the whole of Great Britain, each GP surgery is assigned a private IP Address from Class A or Class B (10.x.x.x or 172.17.x.x) private ranges.
Within each GP surgery the individual computers have a Class C private IP (192.168.x.x)
So it's a NAT within a NAT.
But when I got to WhatIsMyIP or something similar I get a 194 address, that is the external gateway of the whole N3 network out to the internet. I want the 10.x.x.x or 172.17.x.x address of the building.
How do I find out the 'external' IP Address if it is internal to another larger private network.
Your best option is going to be to run the TraceRT command within Windows (hoping it's windows O/S).
Start, Run, CMD then click OK. At the DOS prompt, type tracert whatismyip.com and hit enter. Each hop is a step towards the end, in this case whatismyip.com. The first hop will be the computers local IP, the second hop should be the IP of the router to which the PC is connected, etc. You'll then need to decipher which IP belongs to which device.