Azure Logic Apps Fails to Connect to SQL Managed Instance: "The server was not found or..."

Question

I am trying to connect an Azure Logic App (Standard) to an Azure SQL Managed Instance (MI). Both the Logic App and SQL Managed Instance are within the same Virtual Network (VNet) but reside in different subnets with separate Network Security Groups (NSGs).

Here’s what I’ve already done:

Network Configuration:

• Enabled VNet integration for the Logic App and pointed it to the same VNet where the SQL Managed Instance resides.
• They are within same Virtual Network. Subnets and nsg's are different for Virtual jumpbox, Sql Managed Instance and Logic App
• There is a outbound rule in the nsg of Logic app to allow outbound traffic from Logic App's subnet to SqlServer MI's subnet on port 1433
• There is a inbound rule in the nsg of SqlServer MI to allow traffic from Logic App's subnet to SqlServer MI's subnet on port 1433

Connection Settings: Public endpoint access is disabled for the SQL Managed Instance as per company policy. Tried connecting via the private IP and DNS name of the SQL Managed Instance.

Testing:

I successfully connected to the SQL Managed Instance using the public endpoint on port 3342 (before disabling it for compliance).

Error: When trying to execute a query from the Logic App, I get the following error:

A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible.

Answer 1

Azure Logic Apps Fails to Connect to SQL Managed Instance: "The server was not found or..."

The Logic App connector traffic will go through multiple public IPs. You can find the Logic App public IPs here based on the region. Since there is no option in SQL Managed Instance to allow traffic from Logic App region connectors' IPs, you can enable the public endpoint and create an inbound NSG rule to allow traffic to SQL only from the Logic App connector, using port 3342. This way, you can restrict public traffic and allow only Logic App traffic on port 3342.

To establish a secure connection between the Logic App and the SQL Managed Instance, you can create an NSG rule that allows inbound connectivity from all Logic App connectors in the SQL MI subnet by enabling the public endpoint in SQL MI.

Attach the NSG to SQL MI Subnet.

Referecne: Available service tags

Configure public endpoints in Azure SQL Managed Instance