SQL Server security: How easy it is to troubleshoot Login failed for user ‘(null)’ kind of errors?

Whenever we talk about login errors it is nothing but SQL Server is not allowing any authentication for that login to connect. The basic principle followed by SQL Server authentication rlies on the internal user list and based upon the authentication type you define the connectivity will be succeeded. Like my fellow MVP Pinal Dave said some errors never got old, and it is one of the frequently asked questions in SQL Server forums about the following error messages (you might have come across too):...(<a href="http://sqlserver-qa.net/blogs/perftune/archive/2010/09/22/9582.aspx">read more</a>)<img src="http://sqlserver-qa.net/aggbug.aspx?PostID=9582" width="1" height="1">