Proxmox 6 Communication Failure (0)


May 23, 2019
Hey guys,

I've set up a cluster with two nodes. On the interface of the main node I can see both nodes as online.
The only thing I can see on the webUI is the summary of the second node, nothing else.

If I try to log in on the webUI of the second node I get the error message: "Connection failure. Network error or Proxmox VE services not running? "
Both nodes can ping each other and on both nodes "pvecm status" seems fine.

Hopefully someone can help me with this one. If you need any logs, just tell me and I'll be happy to provide id.

Okay, I know what the issue is.
I flushed my iptables completly and now the webinterface works on both ends and I can manage both nodes on the main webui.
But that's not the solution. I've opened up my iptables with the ports mentioned in Proxmox-Firewall.

What ports do really need to be opened for my Proxmox 6 cluster to work?

Best regards

EDIT: Okay seems it was port 85 which is not documented at all. Can anyone tell me if this is intended to be opened?
Last edited:
but when it listens on only, why do I even have to open up the port?
it's used to communicate with the pvedaemon socket internally. things probably won't work as expected if you close the port


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