I think this might be a network routing issue rather than SQL. Can you ping or traceroute the server from the local desktop or laptop?

Thank you for your help.

All,

Thanks for your help.

Both,

Thank you for your help.

Jonathan: Thanks, I hadn't realised it had rounded to an int. Am I correct in thinking that AVG will return an int if it receives an...

Alejandro Santana,

Thanks for the update.

SPN's is outside of my knowledge unfortunately. The information here might help you https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/prereqs-restrictions-recommendations-always-on-availability?view=sql-server-ver15

Where did you find the error message?

Thanks. The screenshot says that it failed during the post login stage so I think the connection attempt started. Is there anything in the Windows Event Log?

I don't know exactly...

Sorry I don't know the cause of this at the moment. Is there anything in the SQL server logs at the time of the failed connection?

I am just looking at the 1st point in your original post again. I think there should be four possible combinations?:

1. AD account connecting to the listener
2. AD account connecting...

When you change between an AD account and a local SQL instance are you using the same Windows login on the same machine? I'm guessing you already checked but I...

I don't think Glen_A will be able to enable readable secondary as they are using Standard Edition?

As an addition to Jonas' idea perhaps the reply needs to come from an account that has existed for a certain length of time and/or has a certain number of...

Sqltester1: Jeff Moden is correct. Sorry I didn't think of the possibility of using the ID column. Perhaps let us know if you are able to pivot the data in...

Apologises if I missed something but where is the link between each vendor and server name? The only link I can see is the order of the insert statements. Unfortunately...

I am not a network security expert so please don't implement my suggestion without your own research. If the firewall provides VPN functionality then that maybe a suitable option? I...