I am attempting to assign a VNET to the Azure Function on Flex Consumption plan. I am performing the following steps Login to Azure Portal and open function resource Go to Networking Under Virtual Network Details click on "not configured" Click "Add virtual network integration" Select my virtual network resource, and subnet of default (10.0.0.0 - 10.0.0.255) After about 60s I get a notification "Connecting site to virtual network: Failed to connect to the virtual network: An error has occurred." I don't have support plan, but when I tried to open ticket I performed the diagnostics and it said that my VNET is good and I should be able to add it.

Error when assigning Virtual Network to the Azure Function

Dmitriy Konyayev 60

I am attempting to assign a VNET to the Azure Function on Flex Consumption plan. I am performing the following steps

Login to Azure Portal and open function resource
Go to Networking
Under Virtual Network Details click on "not configured"
Click "Add virtual network integration"
Select my virtual network resource, and subnet of default (10.0.0.0 - 10.0.0.255)
After about 60s I get a notification "Connecting site to virtual network: Failed to connect to the virtual network: An error has occurred."

I don't have support plan, but when I tried to open ticket I performed the diagnostics and it said that my VNET is good and I should be able to add it.

Silvia Wibowo 3,571 Reputation points Microsoft Employee

2024-06-14T05:16:31.92+00:00
Hi @Dmitriy Konyayev , please check your subnet. Note this limitation of subnet for Azure Function (Flex Consumption) virtual network integration:

The subnet you choose can't already be used for other purposes, such as with private endpoints or service endpoints, or be delegated to any other hosting plan or service.

Create a new subnet in the same vnet to make sure that it's not being used for anything else such as service endpoint, private endpoint, or other delegation.
Pat Clark 0 Reputation points

2024-07-07T14:42:45.48+00:00

I am having the same issue. I am using a subnet that is not used for any other service. I receive the error "Failed to connect to the virtual network: An error has occurred." and I do not see any details in the activity log.

Update: I recreated the Function App through VSCode. When prompted to select a "service plan" I chose "App Service Plan." After that, I was able to use Virtual Network Integration withing the Function App.

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Error when assigning Virtual Network to the Azure Function