Question

Following is my code that I use to connect windows application to my server, But on office machines where limited access to internet, I can not connect i.e. this code fails. I have to use proxy for this. Please help me in writing proxy for following code.

{
TcpClient client = new TcpClient();
client.Connect("98.130.254.199", 0x599);
client.Close();
}

Answer 1

You can't use proxy with raw sockets (i.e. TcpClient)
except creating your own class derived from TcpClient
and implementing SOCKS or HTTP proxy support.
You'd better use HttpWebRequest/HttpWebResponse pair:

using System.Net;
...
HttpWebRequest request = (HttpWebRequest)WebRequest.Create("98.130.254.199");
request.Proxy = new WebProxy("43.59.90.111", 1080);
request.Method = "GET";

using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
{
StreamReader reader = new StreamReader(response.GetResponseStream());
Console.WriteLine(reader.ReadToEnd());
...
reader.Close();
response.Close();
}

By the way, the 0x599 or the 1433 port is usually used to connect to the MSSql server,
so you should use SqlConnection class to do it.