Troubleshooting Login failed Error 18456

Input : select * from sys.sysmessages where error = 18456

Output: Login failed for user ‘%.*ls’.%.*ls%.*ls

This is one of the infamous error message (and number) that most of the DBAs and developers have come across while working on SQL server. This message simply denotes that the client call was able to reach the SQL server and then an ACCESS was denied to the particular login for a reason. To figure out the exact reason, this error number 18456 with its STATE number is logged into the SQL server error log file, if SQL server was allowed or configured to capture the failed logins.


Cross Domain Windows Authentication for SQL Server databases

There are many acquisitions these days and the DBA and sysadmins have a great tasks of doing a cross-domain authentication to their servers and databases. System admins have various options to connect interdomain where as DBA has to look up for it. Here is a solution that one can try using to access databases in cross-domain platform with windows authentication.


How to Copy Move a Database that is encrypted with TDE

In my previous articles on TDE Ive gone through whats TDE and how to configure it. Now here in this article Im going to test whether Im able to restore attach the database without encryption key since the main property of TDE is not to allow to use the physical files of the database without certificate. Ill also brief about how to copy move the database that is encrypted with TDE.


Implementing Transparent Data Encryption (TDE)

In my previous article we have discussed what is TDE, how it works, its pros and cons. In this article Im going to cover how to implement transparent data encryption to your server. Its very simple to implement TDE, below are the steps that needs to be completed to enable TDE.

  • Create a master key
  • Create or obtain a certificate protected by the master key
  • Create a database encryption key and protect it by the certificate
  • Set the database to use encryption

Lets discuss on each of this title to create TDE


Transparent Data Encryption (TDE)


Securing each part and datas in a database is now an important task for DBAs to accomplish else the datas might be hacked. Keeping in mind Microsoft has started encryption features from SQL 2005 and its greatly improved its feature in SQL Server 2008. Lets recall the encryption features in previous versions of SQL Server.