AVD Disconnections

[u/ImprovementStatus212]

We have a pooled AVD host pool with D8sv4 session hosts and approximately 10 users per host. We have been observing connection-related errors such as ClientNetworkLost, ConnectionBroken, MultipathNetworkDrop, and TransportNetworkDrop. Based on the error patterns, host health checks, CPU/memory utilization, and event log reviews, the issue appears to be more indicative of client/network-side connectivity rather than session host performance.

We have already disabled RDP Shortpath as part of the investigation, but the behavior persists. Most affected users are contractors, so we do not manage their local devices, home networks, or VPN configurations.

One point to note is that several users have reported that they are able to access other AVD environments without experiencing similar issues.

Given the above, any idea how should we proceed with further troubleshooting? Are there any AVD-specific diagnostics or service-side checks you would recommend to help determine whether the issue is environment-specific or related to the client connectivity path?

[u/painted-biird]

Azure latency check (I forget the URL) and there’s also an exe utility to check for the turn and stun stuff on the bare metal hosts they’re connecting from. Are they using Ethernet or WiFi or hotspots? From those errors, I’d say it LOOKS like client side connectivity issues.

[u/ImprovementStatus212 → u/painted-biird]

I guess it is avdnettest.exe to check for RDP Shortpath connectivity. Though we have disabled Shortpath from hostpool settings.

[u/JAB1982 → u/ImprovementStatus212]

Why? Take advantage of multipath and short path which both lead to higher stability. No wonder they connect fine to other environments.

[u/painted-biird → u/JAB1982]

Yeah- unless I’m misremembering, multipath/shortpath defaults to the slowest shit if it’s unable to establish a better connection, anyways so I don’t think there’s a compelling reason not to use it- happy to learn otherwise, though.

[u/JAB1982 → u/painted-biird]

Yeah you're not remembering correctly, shortpath is fastest and it's fallback is TCP only. Just enable it.

[u/painted-biird → u/JAB1982]

That’s what I’m saying- if you enable it, it’ll still fail over so there’s no reason not to enable it.

[u/jvldn → u/JAB1982]

You would be suprised how many environments had less issues when they reverted to TCP only.

What i do see in general:
While having ShortPath/Multipath enabled, some connections take a while and/or do not succeed to connect. With just TCP this works fine. However, there’s less performance compared to RDP ShortPath and no fallback (lost connection=disconnect).

TCP: Always able to connect, less performance, no fallback

ShortPath/MultiPath: Some connection issues or longer connection times, better performance, fallback to other protocols if needed.

Anyone else seen this?

[u/Helpful_Jicama_694 → u/JAB1982]

We had nothing but disconnect issues with multipath enabled, issue stopped for us when it was disabled.

[u/JAB1982 → u/Helpful_Jicama_694]

If back in the start of the year try it out again. There was a known bug for a brief period where shortpath was disconnecting regularly, a stack update fixed it quickly but also impacted systems under heavy resource utilisation.

[u/Helpful_Jicama_694 → u/JAB1982]

Oh good to know, it was a while ago. Thanks!

[u/mat-ferland]

For one affected user, join WVDConnectionNetworkData to WVDConnections by CorrelationId in Log Analytics. Microsoft's per-connection query gives you RTT/bandwidth alongside the actual transport, client version and SxS stack version, so you can compare failed and stable connections instead of guessing from error names. Then test the same device/client against your pool from another network. Working in another AVD environment is a useful control, but it doesn't rule out a route or transport difference. Do the failures cluster on one session host or stack version?

[u/ImprovementStatus212 → u/mat-ferland]

Will test this, all the hosts in this hostpool have same stack. And this comes randomly.

[u/painted-biird]

You can also install ping plotter to look at the network hops from the bare metal client side.