public static string GetUserPublicHostAddress(this HttpRequestBase request)
{
var userHostAddress = request.UserHostAddress;
// Attempt to parse. If it fails, we catch below and return "0.0.0.0"
// Could use TryParse instead, but I wanted to catch all exceptions
IPAddress.Parse(userHostAddress);
var xForwardedFor = request.ServerVariables["X_FORWARDED_FOR"];
if (string.IsNullOrEmpty(xForwardedFor))
{
return(userHostAddress);
}
// Get a list of public ip addresses in the X_FORWARDED_FOR variable
var publicForwardingIps = xForwardedFor.Split(',').Where(ip => !IPAddressHelper.IsPrivate(ip)).ToList();
// If we found any, return the last one, otherwise return the user host address
return(publicForwardingIps.Any() ? publicForwardingIps.Last() : userHostAddress);
}
