how to troubleshoot intermittent windows Authentication to SQL

andrewtkh1

Setup:

• OS: Windows 2022
• App: Solarwinds 2025.1
• DB: SQL 2022

Trying to connect the app to DB with a domain account via the config wizard occasionally gives the error "Connection Timeout Expired. The timeout period elapsed while attempting to consume the pre-login handshake acknowledgement. This could be because the pre-login handshake failed or the server was unable to respond back in time." Each step of the config wizard also takes 5~10 seconds to load. This issue doesn't occur when using SQL Authentication.

I was able to complete the config wizard with a domain account once after repeatedly trying. Despite the app working, im still seeing the above error in event viewer repeatedly.

I have not set an SPN & expect Kerberos to fail & fall back to NTLMv2. But im not sure why NTLM is failing.

I've verified with my team that NTLM is still enabled in our env & working for other teams. Also that firewall (windows & network) is not blocking any traffic.

Some of the solutions ive tried are:

1. Increasing the polling & timeout values at SWNetPerfMon.db file.
2. Granting sysadmin & DBO to the domain account.
3. Looked through the AD's event viewer for any Authentication failure.

Any thoughts on where else I could start looking?

marcrobinson

Tracking those event logs by id from windows on the swosh servers is very useful. I have tracked some of those back to sql server issues during same timeframe and been able to track them against network latency also. This will give a dba some input to work with too. Setup netpath to your dbinstance on port 1433 from your pollers - that will point out recurring network issues too. There may be another port worth monitoring, but I cannot think of it now.