How to get a user's client IP address in ASP.NET?

Question

We have Request.UserHostAddress to get the IP address in ASP.NET, but this is usually the user\'s ISP\'s IP address, not exactly the user\'s machine IP address

Answer 1

IP addresses are part of the Network layer in the "seven-layer stack". The Network layer can do whatever it wants to do with the IP address. That's what happens with a proxy server, NAT, relay, or whatever.

The Application layer should not depend on the IP address in any way. In particular, an IP Address is not meant to be an identifier of anything other than the idenfitier of one end of a network connection. As soon as a connection is closed, you should expect the IP address (of the same user) to change.