Jquery-based Standalone Port Knocker

I am working on a small project and need to provide an alternative method for my team members to port knock on a non-production server and open port 22 for SSH traffic (access clos

Solution 1:

You are using GET requests for images to port knock on your server. I assume the server does not reply to these requests and even filters them, so they will eventually time out.

Some browsers might be reluctant to perform the same request if the previous attempts timed out. They may also implement a queue and only send a few requests at the same time, which can cause problems if these requests are still pending when you have to send the next part of your knock (standard TCP timeout being 30 seconds).

If at all possible, reimplement your knocking protocol with WebSockets.

If you're stuck with images, try appending "?" + $.now()to your URLs so they become unique for each request. It might help preventing the browser from giving up on a specific request.