So I was connecting to Microsoft SQL Server and trying to use the SQL Authentication method and I received this event ID error 18456 login failed for user you provided. See below example.
I did some research online and found out that this usually means that your connection request was successfully received by the server name you specified [so why didn't it work], but the server is not able to grant you access for a number of reasons and throws error: 18456.
Below is a list of reasons and some brief explanation what to do:
SQL Authentication not enabled: If you use SQL Login for the first time on SQL Server instance than very often error 18456 occurs because Windows Authentication (only) is set in Server properties (security section).
To Access Server Properties, Open SQL Server Management Studio, go to Object Explorer pane (use view if you can’t see it). Use the connect button to connect to database engine for your server. Once connected you will see it in object explorer. Right click server and click properties. Server Properties window will appear.
See below screenshot that might be causing SQL login to fail
You should set Server Authentication to SQL Server Windows Authentication
Invalid password: Wrong password or just a typo. Remember that this username can have different passwords on different servers.
less common errors: The userID might be disabled on the server. Windows login was provided for SQL Authentication (change to Windows Authentication. If you use SSMS you might have to run as different user to use this option). Password might have expired and probably several other reasons…. If you know of any other ones let me know.
18456 state 1 explanations: Usually Microsoft SQL Server will give you error state 1 which actually does not mean anything apart from that you have 18456 error. State 1 is used to hide actual state in order to protect the system, which to me makes sense. Below is a list with all different states and for more information about retrieving accurate states visit Understanding “login failed” (Error 18456) error messages in SQL Server 2005
|ERROR STATE||ERROR DESCRIPTION|
|State 2 and State 5||Invalid userid|
|State 6||Attempt to use a Windows login name with SQL Authentication|
|State 7||Login disabled and password mismatch|
|State 8||Password mismatch|
|State 9||Invalid password|
|State 11 and State 12||Valid login but server access failure|
|State 13||SQL Server service paused|
|State 18||Change password required|