SQL Server Error 26 troubleshooting checklist

SQL Server Error 26  relates only to SQL Server Named instances. Not default instances

The main reason SQL Server Error 26  error message appears is that the client  can’t receive SQL Server Resolution Protocol(SSRP) response UDP packet from the SQL Browser Service

1) Check the server name is correct? Check spelling.

2) Check the SQL Server instance name , is there such an instance on the target server?

3) Can you ping the server? Is DNS resolvable? Sometimes ping isn’t possible as the administrator  disabled the ping service.

4) Is SQL Browser Service turned on?

5) Is the frewall enabled?If so , place sqlbrowser.exe or port 1434 into the exception list.

6) Is you server part of a Cluster?

 If after these steps the connection is still failing try:

tcp:SEVERNAME\INSTANCE_NAME

Add a comment , if you have a problem – and I’ll assist in troubleshooting.Or another SQL Server DBA will help

 This will give you some extra information to troubleshoot the SQL Server Error 26 message

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