# SQL Server DB unreachable

Last updated: July 24, 2026

## Problem

You are trying to start MDM Server or perform some operation in MDM, when you get the error "SQL Server DB unreachable"

## Cause

This error occurs due to the following reasons:

- [MDM Server cannot access the SQL DB Server](https://www.manageengine.com/mobile-device-management/kb/mdm-sql-server-db-unreachable.html#access)
- [Ports used by SQL Server are being used by other applications](https://www.manageengine.com/mobile-device-management/kb/mdm-sql-server-db-unreachable.html#down)
- [SQL server is blocked by firewall](https://www.manageengine.com/mobile-device-management/kb/mdm-sql-server-db-unreachable.html#firewall)

## Resolution

### MDM Server cannot access the SQL DB Server

Ping the IP address of the SQL server from the machine which is running MDM server. If this is not successful, it implies MDM Server cannot access the SQL DB. Also, ensure the machines running SQL Server and MDM Server are connected to the Internet.

### Ports used by SQL Server are being used by other applications

Telnet the ports used by the SQL server to identify, whether its being used by other applications. If yes, then ensure the ports are used only for the SQL server.

### SQL server is blocked by firewall

Ensure exclusion rules have been setup in firewall and any third-party filters, for all the ports used by SQL server.

**NOTE: If the issue persists, contact MDM Support with the Server logs.**