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brogyi's avatar
brogyi
Brass Contributor
Apr 01, 2025

AVD connecton error

Hi!

We are using Win11 multi user based OS-es. After we installed the 2025-03 march CU update (KB5053657) at weekend the session host started randomly having connection errors. The users experienced this error:

The pool state first:

You can say, the rdp agent are unhealthy of course the joining is not working. Even from the server in the save vnet i cant ping and cant rdp to them. The resolution was to reinstall agents, reboot computers, or deallate, start them, one of needed to be redeployed.

After patch removal the issue seemd to be resolved, there were eventless couple days, yet today it happened again. Today only 2 servers were affected, march update not installed I checked. Agent health state shows all available, yet not able to ping, not able to rdp. One restarted from azure and one deallocated and started and started working. What can be this isse?

Anyone met or experienced the same? How can I trouble shoot this, any idea? Tried searching event log, but I cant see the reason.

AVD
AVD Host Pool
AVD Hosts
AVDUpdate
  • kclang's avatar
    kclang
    Copper Contributor
    Apr 07, 2025

    We are facing this issue as well! Australia datacenter location.

     

    It's becoming a real nuisance for our users.

  • PaulStirling's avatar
    PaulStirling
    Iron Contributor
    Apr 07, 2025

    We are having the exact same issue for the past week. Also removed march update to now help.

    Intermittently Unavailable and Needs Assistance on random machines. Reboot fixes but can happen any time. No other changes on our end made to contribute.

  • kclang's avatar
    kclang
    Copper Contributor
    Apr 07, 2025

    Just confirming we are experiencing the exact same issue in Australia East datacenter, it started a few days ago, went away and now it's back again.

    We're Win 11 23H2 - we uninstalled March updates also due to known (but not published by microsoft) issues with RDP that were introduced.

    Any ideas from anyone would be helpful.

  • Kidd_Ip's avatar
    Kidd_Ip
    MVP
    Apr 03, 2025

    Take this:

     

    1. Investigate the Root Cause
    • Event Logs: Check the Windows Event Viewer on the affected session hosts for errors related to RDP, Azure agents, or network connectivity.
    • Azure Monitor: Use Azure Monitor to review metrics and logs for the session hosts. Look for anomalies in CPU, memory, or network usage.
    • Agent Logs: Review the logs for the Azure Virtual Desktop agent and RDP agent. These logs can provide insights into why the agents are becoming unhealthy.

     

    1. Common Causes
    • Update Compatibility: The March CU update (KB5053657) might have introduced compatibility issues with the AVD agents or network settings.
    • Network Configuration: Ensure that the affected session hosts are correctly configured within the virtual network (VNet). Verify that DNS settings and firewall rules allow communication between the hosts and Azure services.
    • Agent Health: Unhealthy agents can result from corrupted installations or missing dependencies. Reinstalling the agents, as you've done, is a valid workaround.

     

    1. Troubleshooting Steps
    • Reinstall Agents: If reinstalling the agents resolves the issue temporarily, consider automating this process using PowerShell or Azure Automation.
    • Deallocate and Redeploy: Deallocating and redeploying the affected session hosts can reset their state and resolve connectivity issues.
    • Rollback Updates: If the issue persists, consider rolling back the March CU update on all session hosts until a permanent fix is identified.

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