Question:This error appeared in the SQL Server Logs today.Error: 17836, Severity: 20, State: 14. Length specified in network packet payload did not match number of bytes read; the connection has been closed. Please contact the vendor of the client library. [CLIENT: an_ip]
How can I find out what application is attempting to connect ?
Answer:The most common reason for this error are Nessus scanners or similar detection intrusion systems. They usually scan servers looking for vulnerabilities. It’s not obvious from the logs but you can build a correlation between the timings in the SQL Server Error logs and the Nessus Scanner schedules \ logs
The first clue is the CLIENT details specified in the error log. Use the nslookup command to find the FQDN. It may be obvious from the client name , and you can contact the server owner to find out if there are any applications attempting to connect
Another option is to use a network monitor tool to discover exactly which program \ logon is hitting the server.
For more detailed information about the error message use the Troubleshoot connectivity issues with Connectivity Ring Buffer