I have a function trying to access blob storage but giving error when trying to see in Azure

Question

I have a function trying to access blob storage but giving error when trying to see in Azure

Kaipa Venkata Sreedhar Reddy 0

Hi Team,

I have a Azure function and I am deploying code for functions to run on Azure using CI/CD. Evertything is working fine in lower environments but when come to production getting error in function saying that Azure.Core: No such host is known. (xxxx.blob.core.windows.net:443). System.Net.Http: No such host is known. (xxxx.blob.core.windows.net:443). System.Net.Sockets: No such host is known.

Request for help.

Sai Prabhu Naveen Parimi 2,265 Reputation points Microsoft External Staff Moderator

2025-06-12T18:35:59.4333333+00:00

@Kaipa Venkata Sreedhar Reddy

It seems like you're facing a connectivity issue with your Azure Function trying to access Blob Storage, specifically the error message indicating "No such host is known." Here are a few troubleshooting steps you can take:

Check Connection String: Ensure that your connection string in the function's application settings is correct and includes the blob endpoint. You can verify this by going to the Azure portal, navigating to your storage account, and copying the connection string from the Access keys blade.

Configuring App Settings: Double-check the app settings for your function in the Azure portal. Make sure the connection string there references the correct storage account and that there are no typos.

Networking Issues: Make sure there are no networking issues or VNet restrictions that might prevent your function from reaching the Blob Storage.

Validate Environment: Since everything works in lower environments but fails in production, confirm that the production deployment has correctly inherited or set the required environment variables and connection strings.

Logs and Error Details: Check the function app logs for more detailed error messages. The logs can provide insight into whether the iss
Kaipa Venkata Sreedhar Reddy 0 Reputation points

2025-06-12T19:21:05.6533333+00:00

I have checked all the settings and both are in same VNET and double verified the connection strings as well still same issue

1 answer

Your answer

Sai Prabhu Naveen Parimi 2,265 Reputation points Microsoft External Staff Moderator

2025-06-12T18:35:59.4333333+00:00

@Kaipa Venkata Sreedhar Reddy

It seems like you're facing a connectivity issue with your Azure Function trying to access Blob Storage, specifically the error message indicating "No such host is known." Here are a few troubleshooting steps you can take:

Check Connection String: Ensure that your connection string in the function's application settings is correct and includes the blob endpoint. You can verify this by going to the Azure portal, navigating to your storage account, and copying the connection string from the Access keys blade.

Configuring App Settings: Double-check the app settings for your function in the Azure portal. Make sure the connection string there references the correct storage account and that there are no typos.

Networking Issues: Make sure there are no networking issues or VNet restrictions that might prevent your function from reaching the Blob Storage.

Validate Environment: Since everything works in lower environments but fails in production, confirm that the production deployment has correctly inherited or set the required environment variables and connection strings.

Logs and Error Details: Check the function app logs for more detailed error messages. The logs can provide insight into whether the iss
Kaipa Venkata Sreedhar Reddy 0 Reputation points

2025-06-12T19:21:05.6533333+00:00

I have checked all the settings and both are in same VNET and double verified the connection strings as well still same issue

Answer 1

Sai Prabhu Naveen Parimi 2,265 Microsoft External Staff Moderator

@Kaipa Venkata Sreedhar Reddy

Thank you for the update.

Since you've confirmed that the Azure Function and the Storage Account are in the same VNet and the connection strings are correctly configured, the issue might be related to the VNet integration settings of the Function App.

To address this, please add the following application settings in your Function App (under Configuration > Application settings):

vnetRouteAllEnabled = 1  
vnetContentShareEnabled = 1

These settings ensure that all outbound traffic, including traffic to Azure services like Blob Storage, is correctly routed through the integrated VNet.

After adding these settings, please restart your Function App and check if the issue persists.

Sai Prabhu Naveen Parimi 2,265 Reputation points Microsoft External Staff Moderator

2025-06-13T22:59:22.3033333+00:00

@Kaipa Venkata Sreedhar Reddy

I just wanted to follow up to see if the solution worked for your issue. Let us know if you need any further clarification or assistance.
Sai Prabhu Naveen Parimi 2,265 Reputation points Microsoft External Staff Moderator

2025-06-17T00:52:55.2533333+00:00

@Kaipa Venkata Sreedhar Reddy

Just checking in again — were you able to apply the vnetRouteAllEnabled and vnetContentShareEnabled settings and test the function. Please let us know if the issue still persists or if there’s anything else we can help troubleshoot.

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I have a function trying to access blob storage but giving error when trying to see in Azure

1 answer

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