Some websites like http://www.geoip.co.uk are able to get the private IP address of my host where as others like https://www.iplocation.net/ are unable to do so.
What is the reason behind this behaviour? I always thought that private IP is inaccessible to servers if I am using a NAT interface.
Does NAT append the public IP to the outgoing packet or it removes the private IP completely? If the latter is the case, why is the above mentioned behaviour observed?
The 10.9.64.58 is my private IP address (the one I get after ipconfig).
EDIT : As @simlev points out that I should add the following information: I am a university student and am connected to institute's LAN when visiting the site on my PC but I observe the same behaviour on my phone too and my phone isn't on that LAN. Imgur screenshots here and here.
EDIT: Another observation which I feel is relevant : When I visit the website using https:// I get my public IP (the desired thing) but only when I visit it using http:// I get the private IP. So, is there some protocol issue we are talking about here?