Its some-thing not clear about when you are able to connect and not
connect. Via office lan you able to connect VPN and sqlserver with window
auth. But later means?.
Answer is When we use VPN, at the same time we have option to use window
or sqlserver. But we direct connect without VPN, we are not in their lan
and that's why we are not connect with window auth, we must connect with
sqlserver mode only with permission user(s).