Step 1: Determine whether the named instance is using a static or dynamic TCP port

1. Open SQL Server Configuration Manager.
2. Navigate to:
   SQL Server Network Configuration → Protocols for [Instance Name].
3. Right-click TCP/IP and select Properties.
4. Open the IP Addresses tab and review the IPAll section.

Static TCP port configuration

• TCP Port contains a specific port number (for example, 1433 or another fixed port).
• TCP Dynamic Ports is empty.

This indicates that the SQL Server instance is configured to use a static TCP port.

Dynamic TCP port configuration

• TCP Port is empty.
• TCP Dynamic Ports is set to 0.

When TCP Dynamic Ports is set to 0, SQL Server dynamically assigns an available TCP port each time the service starts. The assigned port can be viewed in the SQL Server error log or in SQL Server Configuration Manager after the SQL Server service starts.

Note: If TCP Dynamic Ports contains a value, SQL Server may assign a different port after each restart. To ensure predictable connectivity, configure a fixed port under TCP Port.

Step 2: If the named instance uses a dynamic TCP port

When adding the MS SQL monitor in Applications Manager, enable Connect using Named Instance and specify the instance name. For existing monitors, edit the monitor and update it to use the instance name.

Ensure that the SQL Server Browser service is running on the SQL Server host.

SQL Server Browser and UDP port requirements

Named instances configured with dynamic ports rely on the SQL Server Browser service to resolve the instance name to the currently assigned TCP port.

By default, SQL Server Browser listens on UDP port 1434, although this port can be changed based on the server configuration.

Ensure that the configured UDP port is reachable from the Applications Manager server to the SQL Server host by verifying that it is:

• Open it on the SQL Server host firewall.
• Allowed through any intermediate network firewalls.

If the required UDP port is blocked, or if the SQL Server Browser service is not running, the following error may occur:

java.sql.SQLException: Unable to get information from SQL Server

This error indicates that the JDBC driver was unable to resolve the TCP port associated with the named instance.

Note (SQL Server 2005): On SQL Server 2005, instance name resolution depends entirely on the SQL Server Browser service. By default, this service is disabled and is not configured to start automatically. Enable and start the service before attempting to monitor the instance.

Step 3: If the named instance uses a static TCP port

When a static TCP port is configured:

• Configure the MS SQL monitor using the hostname/IP address and TCP port number.
• The SQL Server Browser service is not required.
• UDP connectivity is not required for instance resolution.

Common causes of connection issues

Verify the following if the monitor cannot connect:

• TCP/IP is disabled for the SQL Server instance.
• The SQL Server service is not listening on the expected TCP port.
• Firewall rules block:
  • The configured a static TCP port, or
  • The UDP port used by the SQL Server Browser service (for dynamic port configurations).
• An incorrect instance name or TCP port is specified while configuring the monitor.
  

Refer to our feature page to learn more about SQL Server monitoring in Applications Manager.