Azure sql port 443

Question

We have an azure sql database which has both ports 1433 and 443 opened. I can use SSMS to connect to the database but the application is getting intermittent response code 500 with the below

Message A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: TCP Provider, error: 40 - Could not open a connection to SQL Server) Exception type System.Data.SqlClient.SqlException

and these errors pointed to port 443.

My question; Sql server by default listens to port 1433. When and what can cause the requests to go to port 443?

Thanks!

Answer 1

An HTTPS connection to SQL Database via URL is through port 443. Here are some cases:

Scenario: SQL Server instance running over an HTTP endpoint. Port: Can be specified when an HTTP endpoint is created. The default is TCP port 80 for CLEAR_PORT traffic and 443 for SSL_PORT traffic.

Scenario: SQL Server default instance running over an HTTPS endpoint. Port: TCP port 443

Feature Analysis Services configured for use through IIS/HTTPS (The PivotTable® Service uses HTTP or HTTPS) Port: TCP port 443

Feature: Reporting Services configured for use through HTTPS Port: TCP port 443