When the issue was found, the KB was released which patches WinNAT's behaviour. WinNAT would reserve the wrong port though - port 36895, which is 1F 90 in hex - so you can see that it read the bytes in the reverse order.Īt this point, my guess is that since after that call, the desired port was not allocated, docker has some workaround code to force allocate said port, and was able to handle the port forwarding. Pre-patch, when the OS received the request it would allocate the wrong port - in my case port 8080 is requested, which is 90 1F in hex. The way I understand it, when the docker engine is trying to expose the port, it requests it from the OS. I think we're either misunderstanding the issue in the KB, or post was a little misleading. Which is exactly the case you're having too In both cases the port that I want to map on the host was not allocated before running the container. Please check my two console dumps above - you can see the allocated ports before and after starting the container.
