Troubleshooting network disconnection in OpManager server

OpManager does a periodic self-ping to ensure that the OpManager-installed server is connected to the rest of the network. If this ping does not get a positive response, it is considered as a 'network disconnection' and data collection is temporarily suspended.

When that happens, an alert is raised as follows:

OpManager has detected that it has lost network connectivity and has suspended all monitoring. Monitoring will be automatically resumed once connectivity is established.

The data collection will be re-initiated once the self-ping is successful.

The possible causes for the network disconnection alert are as follows:

  1. The OpManager-installed server has been disconnected from the network
  2. IP Address/Hostname changes or any network-related changes have occurred for the OpManager server.
  3. Entries in the etc\hosts have been modified recently or some misconfiguration has occurred in the etc\hosts file.

How can I troubleshoot this network disconnection error?

  1. Get the network address we detected during startup.
    • Go to Alarms → All alarms and click on the Search icon in the top right corner, and search for "network connectivity" under the Message column.
    • Look for the latest instance of either of these messages:

      OpManager has detected that it has lost network connectivity and has suspended all monitoring. Monitoring will be automatically resumed once connectivity is established.
      (OR)
      Network connectivity reestablished. Resuming network monitoring services.

      If you're using OpManager in other languages, search for "OpManager" in the Category field and look for the equivalent of the message mentioned above.
    • If the latest message says "Network connectivity reestablished" it means that data collection has resumed, and you can safely close the popup message.
    • If the latest message says that network connectivity has been lost, note down the IP Address/Hostname of that message under the "Source" column. Let's call this as Source 1.
  2. Ping local host server and obtain latest IP Address/hostname:
    From the OpManager-installed server, run the "hostname" command on Command Prompt. Note down the hostname and try pinging it to make sure that it's resolving properly with the IP address.
    • If it responds with the local loopback address (127.0.0.1), then you have to check the etc\hosts file. With proper consultation with your network administrator, check and update the etc\hosts file and check the behaviour again.
    • If the response isn't as mentioned above, note down the IP address/hostname mentioned. Let's call this as Source 2.
  3. If Source 1 and 2 are the same, then it means that the network connection is fine now and data collection will be started automatically. You can safely close the pop up message.
  4. But if both are different, then some network change has occurred recently. If that is the case, we recommend you to restart OpManager service once to re-establish the network connection properly.
  5. Even after restarting if you keep getting the same alert, and Source 1 isn't the IP address/hostname of the OpManager-installed server:
    • Run the "ipconfig" command and confirm whether the Source 1 IP has been assigned for any other network adapters.
    • If the IP is not listed at all, then run the below command after proper consultation with your network administrator.

      ipconfig /flushdns

      (Note: This command will refresh the IP vs. DNS entries.)

    • Finally, restart OpManager service and check if data collection is proceeding properly.
  6. If there are issues even after trying all these, try restarting the OpManager service for one last time. If it's still not resolved, obtain the Support Information File (SIF) along with screenshots of the alerts and contact our support team to assist you with this issue.
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