Why can the network disappear on Proxmox KVM?

Question

linux

Good day.
Help to understand the problem, plz.
There is a small game project. Everything works on 2 pieces of iron from Hetzner, on top of ProxMox 5.2-12 and on top of KVM. For some time now, I noticed that the game (in this case, Minecraft) freezes up from time to time and throws me or the players out.
I started to collect stack traces from the game, brought to the connection to the database (if anything - there are pulls, it doesn’t connect every time :)). Further, by sorting through the options, I found out that any connection between the virtual machines with the game and the database (mysql) is lost. Not even ICMP responds. It does not disappear evenly, at different intervals of time. Between these machines there is Mikrotik (shares the gaming network and the database network). I sinned against him, made a direct network between them. Problem still exists. Changed OVS Bridge to Lonux Bridge (you never know...) - similarly
I hung up the same monitoring on other connections (site-database, zabbix-database, zabbix-game etc) and noticed that a similar problem is everywhere, even on the second machine - the connection between virtual machines also disappears.
The logs are clear, except for "netlink: 'ovs-vswitchd': attribute type 5 has an invalid length." in dmesg, but the time does not match in any way. The only thing that I have not tried is that I have not rebooted the piece of iron, I will try today. True, due to the problem on both servers - it's hard to believe that it will help ...
Maybe someone came across or have ideas? ...
PS: Reboot did not help :(

Answer 1

I have an idea. I apologize in advance that it is not technical. Prox has been around for a long time and the current version is 5.0-30. I did not come across anything like this, however, there were no connections between virtual machines. All virtual machines work according to the principle: VM <--> realPC
When I chose Prox, I thought like this: if tasks grow and there are projects, then you can buy a subscription - let the developers answer questions. Maybe it's time for you?
By the way, can't the problem be inside the vm?