I've found this guy in my SQL log:
"The prelogin packet used to open the connection is structurally invalid; the connection has been closed. Please contact the vendor of the client library. [CLIENT: xx.x.xx.xxx]
Error: 17828, Severity: 20, State: 4."
but I can't find any information on it.
We are running SQL 2005 Enterprise (x86) - SP2 and the error is coming from the AD server. The users are getting errors on the application side - "Connection failure". It's random too and I can't reproduce it.
Does anyone know how to fix this (besides 'contact the vendor')?