I can't create a host pool

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I can't create a host pool

Ioannis D. Papaioannou 0

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Himanshu Shekhar 6,145 Reputation points Microsoft External Staff Moderator

2026-05-07T16:48:02.7+00:00
The deployment is failing at the step involving the Microsoft.PowerShell.DSC extension, with the following key error:

“The DSC Extension failed to execute: Error downloading … Unable to connect to the remote server.”

The virtual machine itself has been successfully created, and the failure is occurring at the extension execution

Based on the error message, the DSC extension is attempting to download its configuration from an Azure Storage endpoint:

https://wvdportalstorageblob.blob.core.windows.net/...

However, the VM is unable to establish a connection to this endpoint.

In Azure, the DSC extension depends on outbound HTTPS (port 443) connectivity from the VM to retrieve configuration artifacts. When this connectivity is unavailable, the extension cannot proceed and the deployment fails.

This issue is caused by a lack of outbound network connectivity from the VM to the required Azure Storage endpoint, preventing the DSC extension from downloading its configuration.

Please perform the following checks from the affected VM:

Validate outbound connectivity

Run the following command: Test-NetConnection wvdportalstorageblob.blob.core.windows.net -Port 443

Verify DNS resolution - nslookup wvdportalstorageblob.blob.core.windows.net

Review Network Security Group (NSG) rules

Ensure outbound rules allow:

Destination: Internet

Port: 443 (HTTPS)

Protocol: TCP

Check route table (if applicable)

If a custom route table (UDR) is in use:

Confirm there is a valid route to the internet

Ensure traffic is not blocked or redirected without proper access

Validate firewall or proxy configuration

If your environment uses:

Firewall

Proxy

Private network restrictions

Ensure the VM can reach:

*.blob.core.windows.net

over HTTPS.

Once outbound connectivity is restored:

Retry the deployment (Redeploy option), or

Remove and reapply the failed DSC extension
Himanshu Shekhar 6,145 Reputation points Microsoft External Staff Moderator

2026-05-08T12:48:37.92+00:00

Ioannis D. Papaioannou - Just checking if provided response was helpful! please let me know if you have any queries.

1 answer

Your answer

Himanshu Shekhar 6,145 Reputation points Microsoft External Staff Moderator

2026-05-08T12:48:37.92+00:00

Ioannis D. Papaioannou - Just checking if provided response was helpful! please let me know if you have any queries.

Answer 1

Hey Ioannis, it looks like your host‐pool deployment is getting all the way to the VM creation but then the PowerShell DSC extension can’t pull down its config ZIP from the WVD storage endpoint:

The DSC Extension failed to execute: Error downloading … Unable to connect to the remote server.

That almost always means the VM can’t reach https://wvdportalstorageblob.blob.core.windows.net over HTTPS. Here’s how you can troubleshoot and fix it:

Validate outbound connectivity
- On the VM run:
```
     Test-NetConnection wvdportalstorageblob.blob.core.windows.net -Port 443
```
- If it fails, you know traffic on 443 is blocked somewhere.
Check DNS resolution
- On the VM run:
```
     nslookup wvdportalstorageblob.blob.core.windows.net
```
- Ensure it resolves to a public IP and you’re not accidentally hitting a private DNS zone.
Review NSG outbound rules
- Make sure there’s an outbound rule that allows TCP/443 to “Internet” or at least to the Storage service tag.
Examine route tables (UDRs)
- If you’ve assigned a custom route table, confirm there’s a valid default route (0.0.0.0/0) to your internet egress (NAT gateway, firewall, internet).
Inspect any firewalls or proxies
- If you’re using Azure Firewall, on‐prem proxy, or a network virtual appliance, check that it’s not blocking or inspecting that storage endpoint.
- Some firewalls require you to explicitly allow the FQDN or the storage account’s service tag.

Once you restore 443 connectivity to that blob endpoint, you can:

Hit Redeploy on the failed extension in the portal
OR Remove & reapply the Microsoft.Powershell.DSC extension via PowerShell/ARM

Let me know if that gets you past this error!

Reference docs:

Troubleshoot the DSC VM extension on Windows VMs – https://aka.ms/vmExtensionDSCWindowsTroubleshoot
Understand outbound network dependencies for Azure VMs – https://learn.microsoft.com/azure/virtual-network/troubleshoot-outbound-connection-problems
Create and manage Azure Virtual Desktop host pools – https://learn.microsoft.com/azure/virtual-desktop/create-host-pools-portal

Feel free to share the results of your Test-NetConnection/nslookup or any custom NSG/UDR details if you’re still stuck.

Note: This content was drafted with the help of an AI system. Please verify the information before relying on it for decision-making.

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I can't create a host pool

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