@
Melvin
It is great that you have such a vast experience with Open Game Panel and Counter-Strike 1.6.
While I might have stopped playing all of these games years ago I used to host game servers myself for Counter-Strike 1.6, Counter-Strike: Source, Garry's Mod, Team Fortress 2 and even Counter-Strike: Global Offensive since 2009 for many communities I have worked with / for. I made countless tutorials for game server setups for various games on the Internet.
You always think that you know everything when doing this for years? And that's the first mistake. You never stop learning. There are many things that can hinder the game server from working properly. Addons can cause issues, misconfigurations can lead to problems and etc. Metamod, despite its age, can sometimes be really unstable together with AMXMOD (Metamod-p ftw). Dproto development stopped in 2017.
If all of this you can account for that it works properly then you can end the day with a smile on your face and be proud. If on the next day, despite no visible issues, things stop working then there is maybe something else that is wrong. That something else might be out of your control.
I understand that you might think that all the little errors play no role. My experience is different. The steamcmd errors due to missing files might not be an issue with Counter-Strike 1.6 but with other game servers. I have been using steamcmd when it was in beta and HLDS was still a thing. Even afterwards when HLDS was deprecated and steamcmd became the king there have been issues with those small errors.
When I setup a fresh copy of Counter-Strike 1.6 game server files from steamcmd I couldn't connect initially, too. For a fraction of a second I was stunned but then I saw the two errors about the missing files "listip.cfg" and "banned.cfg". I stopped the game server, created the files, started the game server again and could immediately without any issues.
So no matter how unimportant some errors might be, you might still want to look into them. A few unimportant missing files can make all the difference.
You should end your obessions towards the firewall of your VPS. There is no issue with the firewall. It is a wide open gate as it has been setup so by default on OpenVZ with all policies being set to ACCEPT --> allowing all connections to go in / out. I have two officially certified work degrees in IT: Information Technology Assistant and IT Specialist for system integration. Especially the second degree is deeply connected to networking, firewalling and etc.
So when I tell you that the firewall of your VPS is no issue you can believe it. If you choose not to... so it be. You're out of luck. I know how iptables works.
Remember Host4Fun is using OVH... blackbox DDoS protection. You never really know how it works. UDP traffic that the game servers are based on is especially a problem for DDoS protection.
All of the time you keep blaming iptables... could be simply OVH DDoS protection playing a fool or some issue with the OVH network.
@
deanhills
I cannot fully rule out other issues. To do that you need time and you have to experiment with different setup of the game servers. You also need to do a lot of testing with other people from different part of the worlds.
Like I said before there might be issues that don't seem so important but are actually the big fool that breaks everything. Or it's simply out of our control.
@
Rehan
Well, for all it is worth. These things usually don't make any sense. However if there is an issue at hand it might cause the game server to go down after a certain time despite Open Game Panel saying it is up and running or even the console saying it is running.
As I mentioned before. I guess you either live with it or get another VPS and try it there. I have nothing more to add to all of this.