Randomly cannot ping or connect to server

[Kaydax]

While running a server under mineginx, sometimes minginx just never can be pinged by a client. This happens randomly even when there are clients already connected and are able to ping the server.

Nothing in the logs say anything, proxy is up and running and not crashing.

[Folleach]

This is a very tough type of errors that is hard to debug without network analysis.
I have never seen anything like this, but if I did, the first thing I do is run tcpdump to check if packets are reaching mineginx and if they are being sent out to the upstream address.

Without context, I have nothing to say to this, unfortunately.
But I will keep it mind; if I suddenly think of potential problem, I will check it out