Help with MSSQL Untrusted Domain Error on Windows 2025
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TechyNinja42
I'm dealing with a frustrating issue connecting to an MSSQL server from a web server, both running on Windows 2025. The error I keep getting is "login is from an untrusted domain," even though both servers are on the same domain. I've checked firewall settings, confirmed that I can connect from other servers using my credentials, and verified the SPNs for the MSSQL service, which seem to be correctly configured. The SQL service runs as a gMSA, which has worked fine on other servers. I'm really stuck here—any advice on what to check or try next would be appreciated!
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Just a thought, do you happen to have a 2025 Domain Controller? I’ve heard about some compatibility issues with that version which might affect authentication.
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Have you tried running the command `setspn -L SERVERNAME` to check the registered SPNs for your server? It's crucial to ensure that the account running the MSSQL service has an SPN assigned. If it's a gMSA, it should already have the right SPNs set. You could try adding SPNs manually with `setspn -S MSSQLSvc/sql01.domain.com:1433 DOMAINservername$` and `setspn -S MSSQLSvc/sql01.domain.com DOMAINservername$`. Also, double-check if it's a default instance or named instance, as that affects what SPNs are needed.
TechyNinja42: Thanks for the tips! The gMSA account is indeed correctly running the MSSQLsvc, and the SPNs you mentioned are registered. The domain admin had to register them since I don't have permission to do that myself. Fingers crossed, I find something that helps with this issue!
NetworkGeek99: That’s a bummer. Just be aware that if it’s a named instance, you might need additional SPNs specific to that instance. It can get a bit tricky!
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TechyNinja42: Yes, there is a 2025 DC in the mix. I've heard similar things, and we’re supposed to be upgrading soon to resolve these kinds of issues. It'll be interesting to see if it helps!