Get external IP address over remoting in C#

Question

I need to find out the external IP of the computer a C# application is running on.

In the application I have a connection (via .NET remoting) to a

Answer 1

Patrik's solution works for me!

I made one important change. In process message I set the CallContext using this code:

// try to set the call context
LogicalCallContext lcc = (LogicalCallContext)requestMessage.Properties["__CallContext"];
if (lcc != null)
{
    lcc.SetData("ClientIP", ipAddr);
}

This places the ip address in the correct CallContext, so it can later be retrieved with GetClientIP().