Getting the IP address of server in ASP.NET?

This should work:

 //this gets the ip address of the server pc

  public string GetIPAddress()
  {
     IPHostEntry ipHostInfo = Dns.GetHostEntry(Dns.GetHostName()); // `Dns.Resolve()` method is deprecated.
     IPAddress ipAddress = ipHostInfo.AddressList[0];

     return ipAddress.ToString();
  }

http://wec-library.blogspot.com/2008/03/gets-ip-address-of-server-pc-using-c.html

OR

 //while this gets the ip address of the visitor making the call
  HttpContext.Current.Request.UserHostAddress;

http://www.geekpedia.com/KB32_How-do-I-get-the-visitors-IP-address.html

The above is slow as it requires a DNS call (and will obviously not work if one is not available). You can use the code below to get a map of the current pc's local IPV4 addresses with their corresponding subnet mask:

public static Dictionary<IPAddress, IPAddress> GetAllNetworkInterfaceIpv4Addresses()
{
    var map = new Dictionary<IPAddress, IPAddress>();

    foreach (var ni in NetworkInterface.GetAllNetworkInterfaces())
    {
        foreach (var uipi in ni.GetIPProperties().UnicastAddresses)
        {
            if (uipi.Address.AddressFamily != AddressFamily.InterNetwork) continue;

            if (uipi.IPv4Mask == null) continue; //ignore 127.0.0.1
            map[uipi.Address] = uipi.IPv4Mask;
        }
    }
    return map;
}

warning: this is not implemented in Mono yet

The below snap is taken from Mkyong to show the networks tab inside developers console in google chrome.Inside "Request Headers" tab you could see a list of all server variables as shown below:

Below are few lines of code which gets the ipaddress of the client which hits your application

//gets the ipaddress of the machine hitting your production server              
string ipAddress = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"]; 

if (ipAddress == "" || ipAddress == null)  
{                                     
  //gets the ipaddress of your local server(localhost) during development phase                                                                         
  ipAddress = HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];              
}

//Output:                                                                           
For production server - 122.169.106.247 (random)
For localhost         - ::1