SQL Server listeners Verifying and troubleshooting SQL Server listener connectivity via tcp, named pipes or shared memory connections is a key component in a DBA’s armoury but often overlooked until it’s too late and application teams call up complaining their apps can’t connect. SQL Server can listen for connection requests via multiple listeners, such as TCP/IP, shared memory or named pipes, but sometimes it’s necessary to check connectivity by a specific listener.
With a little help from SQL Server’s tracing tools you can easily get to the bottom of almost all login failures (18456 errors). If the login failure is against SQL Server 2005 or above and the default trace is running just go to my SQL Server default trace post. If you’d prefer to use extended events (as SQL Profiler is now deprecated), go to Capturing login failures via SQL Server Audit.