Ubuntu VM on Azure completely unresponsive after CI/CD pipeline run, even after redeployment

Question

I recently created a new Ubuntu VM on Azure and successfully accessed it via SSH. I then ran a CI/CD pipeline that made three connections to the VM (for frontend, backend, and one other connection). After the pipeline completed, I can no longer access the VM via SSH, and even pinging the VM's IP address fails. The issue persists even after redeploying the VM.

Details:

• New Ubuntu 24.04 LTS VM on Azure
• Initially, SSH access was working fine
• NSG rule allows SSH (port 22) from any IP
• CI/CD pipeline (using GitHub Actions) connected successfully
• After pipeline completion, all connectivity to VM lost (SSH and ping)
• VM status in Azure portal shows as running
• VM agent status is reported as ready
• Redeployment of the VM did not resolve the issue
• Ping to the VM's IP address does not return any response, despite the VM showing as started

Steps Taken:

1. Verified VM is shown as running in Azure portal
2. Checked NSG rules - SSH still allowed
3. Attempted to access via Azure Serial Console
4. Reviewed CI/CD logs for potential network configuration changes
5. Redeployed the VM, but the issue persists

Questions:

1. What could cause a VM to become completely unresponsive after a CI/CD run, even surviving a redeployment?
2. Are there any Azure-specific networking issues that might lead to this situation?
3. How can I troubleshoot network connectivity when the VM appears to be running but is completely unresponsive?
4. What additional diagnostics or logs should I check to identify the root cause?
5. Could this be related to a broader Azure networking issue, and if so, how can I verify this?

Any insights, suggestions, or similar experiences would be greatly appreciated. Thank you!

Answer 1

Bonjour,

Merci d'avoir sollicité la communauté Q&A France.

Suivez les étapes de dépannage décrites dans les articles suivants:

Troubleshoot SSH connections to an Azure Linux VM that fails, errors out, or is refused

Detailed SSH troubleshooting steps for issues connecting to a Linux VM in Azure

Cordialement,

Nina