Multiple Proxy Servers

The main task of these two popular technologies is to provide security for the Internet user. Despite a certain similarity of tasks, they are performed absolutely differently. Proxy, although it allows you to remain anonymous and bypass blocked sites, it is still quite vulnerable, especially when it comes to untested services. VPN in this regard looks preferable, because thanks to end-to-end encryption it reliably protects information from the entry point to the exit point.

To send a UDP request to a STUN server in C++, you can use the following example code. This example uses the boost::asio library for handling asynchronous I/O operations and boost::beast for handling UDP communication. Make sure you have the Boost library installed on your system before running this code.

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

namespace http = boost::beast::http;

using tcp = boost::asio::ip::tcp;
using udp = boost::asio::ip::udp;

int main(int argc, char* argv[]) {
  if (argc != 3) {
    std::cerr << "Usage: stun_udp_request  " << std::endl;
    return EXIT_FAILURE;
  }

  boost::asio::io_context ioc;
  udp::resolver resolver(ioc);
  udp::resolver::results_type results = resolver.resolve(argv[1], argv[2]);

  if (results.empty()) {
    std::cerr << "Cannot resolve: " << argv[1] << ":" << argv[2] << std::endl;
    return EXIT_FAILURE;
  }

  udp::socket udp_socket(ioc);
  udp_socket.connect(results.begin()->endpoint());

  // Prepare the STUN Binding Request
  std::string stun_request =
      "BINDING_REQUEST\r\n"
      "MIXED_RELAY\r\n"
      "USER-AGENT: STUN-UDP-Example\r\n"
      "\r\n";

  // Send the STUN Binding Request
  boost::system::error_code ignored_error;
  udp_socket.send_to(boost::asio::buffer(stun_request), results.begin()->endpoint(), 0, ignored_error);

  // Receive the STUN Binding Response
  boost::beast::flat_buffer buffer;
  http::response response;
  udp_socket.receive_message(buffer, response);

  // Print the STUN Binding Response
  std::cout << "STUN Binding Response:\n";
  std::cout << response.what() << std::endl;

  return EXIT_SUCCESS;
}

To compile the example, you can use the following command:

g++ -std=c++17 -o stun_udp_request stun_udp_request.cpp -lboost_system -lboost_as

If you can't proxy requests in Scrapy:

- Verify correct proxy configuration in Scrapy settings.
- Confirm proxy functionality with external tools.
- Check for typos or errors in your code and settings.
- Ensure proxy authentication details are correct.
- Test with a direct internet connection to isolate the issue.
- Check for IP blocking by the target website.
- Confirm proper configuration of the HttpProxyMiddleware.
- Use Scrapy logging to inspect requests and responses.
- Ensure your proxy supports HTTPS if needed.
- Test with a single, static proxy for simplicity.
- Keep Scrapy and dependencies up to date.
- Consider using middleware libraries like scrapy-rotating-proxies.

Using the "Start" button, go to the search engine and type regedit into it. Once the registry editor opens, go to the address you specified: HKEY_CURRENT_USER\Software\Policies\Microsoft, and then click on the Microsoft folder. On the "New" submenu, select the "Key" option, name it Internet Explorer and click on enter. Now right-click on the Control Panel key you have created and select the DWORD (32-bit) Value option on the "New" submenu. Give the key a name Proxy, and then click enter. In the created DWORD parameter, put 1 instead of 0, click on "OK" and reboot the computer.

A proxy server is a kind of "mediator" between your equipment and a remote server (or the whole Internet). It can be used, for example, to swap your real IP address for another one, to bypass blocking. Proxies can also be actively used to intercept traffic (e.g. when testing created web applications).