Hyper-V cluster network "Partitioned"

James Edmonds 811 Reputation points


We have a 4 node 2019 failover cluster running Hyper-V VMs.
We have started seeing that one of our networks is showing as "Partitioned" as below:

The nodes can ping each other on that network, port 3343 is open, and there are no firewalls in between the nodes.
The cluster is currently operating correctly as far as I can see, but I'd like to resolve this error to prevent any possible issues.

Can anyone advise how to correct this?


Windows Server 2019
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A Microsoft server operating system that supports enterprise-level management updated to data storage.
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A Windows technology providing a hypervisor-based virtualization solution enabling customers to consolidate workloads onto a single server.
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Windows Network
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Windows Server Clustering
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Windows Server: A family of Microsoft server operating systems that support enterprise-level management, data storage, applications, and communications.Clustering: The grouping of multiple servers in a way that allows them to appear to be a single unit to client computers on a network. Clustering is a means of increasing network capacity, providing live backup in case one of the servers fails, and improving data security.
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Accepted answer
  1. Aspall IT 436 Reputation points

    After I disabled and re-enabled cluster and client traffic on this network, even though I made no changes to host or switch side network config, the network status restored to normal.
    I'll be keeping an eye on it to ensure stable, but this does seem to have resolved the issue, and doesn't seem to have been config related.

    Many thanks

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2 additional answers

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  1. Limitless Technology 39,506 Reputation points

    Hello @James Edmonds ,

    Thank you for your question.

    Your problem is most often caused by an incorrect network configuration, or other possible ones are caused ​​by NIC not having been installed correctly, if the third party solution listed below does not work, try removing hidden devices (adapters) in device manager, update the server firmware to the latest then monitor this issue again.

    Use the link in the topic below that has a problem similar to yours, I believe it will be useful for you:



    If the answer is helpful, please vote positively and accept as an answer.

  2. Eric Siron 1,256 Reputation points MVP

    In Failover Cluster Manager:

    1. Start on the Networks node
    2. Highlight the troubled network ("Cluster Network 1" in this case)
    3. At the very bottom of the FCM window, look for the Summary and Network Connections tabs. Switch to Network Connections
    4. In the pane that contains those tabs, in the space above the tab that you just clicked, look for clues

    This space shows the hosts and adapters that have presence in this network by assigned IP address and netmask. Unfortunately, ping is not terribly useful in this case.
    I have only seen it happen once, and that appeared to be because my physical switch and the Hyper-V virtual switch could no longer agree on VLAN frames. I only did cursory troubleshooting and did not discover anything. I believe the problem lies with the physical switch, as I have dozens of similar configurations and only the one displayed the problem. Removing the virtual adapters from their VLANs and relying on layer 3 isolation worked for me.