Why am I experiencing connectivity issues with my Azure SQL Database, including pre-login handshake errors and semaphore timeout period expired errors, and how can I resolve this?

Question

Why am I experiencing connectivity issues with my Azure SQL Database, including pre-login handshake errors and semaphore timeout period expired errors, and how can I resolve this?

PS - Based on common issues that we have seen from customers and other sources, we are posting these questions to help the Azure community.

Answer 1

Greetings!

The connectivity issues with your Azure SQL Database, including pre-login handshake errors and semaphore timeout period expired errors, are likely due to your firewall rules not encompassing a new Microsoft IP within the authorized subnets. This misconfiguration leads to authentication failures, preventing sessions from opening on your database.

Update Firewall Rules: Ensure that your firewall rules include the necessary Microsoft IP ranges. Azure services require specific subnets to be allowed through your firewall for proper connectivity

Follow Azure Documentation: Refer to the Azure public documentation to identify and allow the subnets specified for Azure services. This will ensure that all required IP ranges are covered. Download Azure IP Ranges and Service Tags – Public Cloud from Official Microsoft Download Center

Consider FQDNs with Caution: While using Fully Qualified Domain Names (FQDNs) for firewall rules is an option, be aware that FQDNs can change without notice, potentially causing future connectivity issues. It is recommended to test and validate the use of FQDNs in a non-production environment if you choose to explore this route.

Further Resources: For more detailed guidance on configuring your firewall rules and understanding Azure IP ranges, please refer to the 'Azure IP and Service Tags - Public Cloud' documentation available at [Azure IP and Service Tags Azure service tags overview | Microsoft Learn]

Regards

Geetha