SQL connection error 53 ?

  • SQL Galaxy

    One Orange Chip

    Points: 29228


    windows 2008 R2 64 bit

    SQL 2008 R2 64 bit

    I had checked as below, everythings working fine but not able to connect target database into local client machine.

    1. SQL services are running at target machine

    2. Enable TCP/IP in SQL Server Configuration

    3. Windows Firewall services disabled (switched off)

    4. Enabled Remote Connection

    5. Enabled SQL Server Browser Service

    Still facing connection error number 53



  • Vikrant S Patil


    Points: 2294

    can you post the complete error message?

    Are you using a alias for the connection?

    Try connecting using IP address suffixed by the port no ( XX.XX.XXX.XX,portno) just on a test basis.

    you can also take a look at the discussion from the following URL:


  • Steve Jones - SSC Editor

    SSC Guru

    Points: 714080

    We really need the entire error message, as noted above. 53 is generic, but there should be something with it to explain things.

    Are you sure that your client is connecting with the correct protocols as well?

  • SQL Galaxy

    One Orange Chip

    Points: 29228

    Error code:

    A Network-related or instance-specific error occured while establishing a

    connection to SQL Server.

    The server was not found or was not accessible.Verfy the instance name is correct

    and the SQL Server is configured to allow remote connection.

    (provider: Named Pipes provider:40-could not open a connection to SQL Server)

    (Microsoft SQL Server, Error:53)

    Check the SQL Server service account


    Telnet services is not running at target machine.

  • Steve Jones - SSC Editor

    SSC Guru

    Points: 714080

    It looks like you're connecting on named pipes. Usually that isn't enabled. Use TCPIP

  • Vikrant S Patil


    Points: 2294

    Building up on Steve's suggestion I would like to suggest that you can try using the following to forcefully use TCP/ IP as a protocol:

    1) For Default instance, you can use TCP:Hostname to connect to SQL Server.

    2) For Named Instance you can use TCP:Hostname\Named instance to connect to SQL Server.

    If SQL server is not listening on default port = 1433, you can also add the port no as a suffix if you have not created a alias

    For e.g.

    1) For Default instance you can use TCP:Hostname,portno to connect to SQL Server.

    2) For Named Instance you can use TCP:Hostname\Namedinstance,portno to connect to SQL Server.

    In case you want to confirm the portno that SQL Server is listening on you can take a look at the startup section in the SQL Error Log and then look further for the section that follows " Server is listening on"

    The information mentioned above is based on the following URL which provides comprehensive information for troubleshooting connectivity issues to SQL Server Database engine.


  • keishahutch


    Points: 11

    It turned out to be the udp port 1433 needed to  be open on the firewall to let users outside the domain access the SQL server instances for my scenario.

    Thank you,

Viewing 7 posts - 1 through 7 (of 7 total)

You must be logged in to reply to this topic. Login to reply