How to test if a proxy server is working or not?

Question

I\'ve got a pretty big list with proxy servers and their corresponding ports. How can I check, if they are working or not?

Answer 1

I like to do a WhatIsMyIP check through a proxy as a test.

using RestSharp;

public static void TestProxies() {
  var lowp = new List { new WebProxy("1.2.3.4", 8080), new WebProxy("5.6.7.8", 80) };

  Parallel.ForEach(lowp, wp => {
    var success = false;
    var errorMsg = "";
    var sw = new Stopwatch();
    try {
      sw.Start();
      var response = new RestClient {
        //this site is no longer up
        BaseUrl = "https://webapi.theproxisright.com/",
        Proxy = wp
      }.Execute(new RestRequest {
        Resource = "api/ip",
        Method = Method.GET,
        Timeout = 10000,
        RequestFormat = DataFormat.Json
      });
      if (response.ErrorException != null) {
        throw response.ErrorException;
      }
      success = (response.Content == wp.Address.Host);
    } catch (Exception ex) {
      errorMsg = ex.Message;
    } finally {
      sw.Stop();
      Console.WriteLine("Success:" + success.ToString() + "|Connection Time:" + sw.Elapsed.TotalSeconds + "|ErrorMsg" + errorMsg);
    }
  });
}

However, I might suggest testing explicitly for different types (ie http, https, socks4, socks5). The above only checks https. In building the ProxyChecker for https://theproxisright.com/#proxyChecker, I started w/ the code above, then eventually had to expand for other capabilities/types.