Check reachability to SQL Server from other application servers

Checking the reachability of SQL Server is one of the key points. After successfully installing the SQL server, the DBA job is to make sure the server is reachable to other required servers such as application servers.

Ideally, to check the reachability, we can use SSMS to connect to that SQL instance, but it is not allowed to install SQL Server Management Studio in application servers. DBAs may verify the server to SQL Server reachability by using simple methods other than installing SSMS and checking.

Check the reachability by telnet client:

By telnetting the destination server IP with a port can check the connectivity

  • Check if TELNET is installed on the source machine by typing ‘telnet’ and enter
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  • A welcome window will open if telnet is already installed (If not installed check with the infra team)
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  • Now telnet the destination [ideally SQL Server] with port
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  • This means either your SQL Server is not running on port 1433 or connection is not allowed from the security side. We have requested to open port 1433 from the source server to the destination server
  • It opens as a blank window which means we have reachability
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Check the reachability by creating a udl file:

  • Another yet simple process to check the connectivity by directly connecting to an instance.
  • Go to the source server, create a .txt file, and change the extension to .udl
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  • This means, you have a reachability between source and destination

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