How can I tell what SQL server instance my server is connected to?
You can find this information following in 2 ways:
Web console:
Database Address: SQL01\MSSQLSERVER
Locally on the server:
[ODBC] DRIVER=SQL Server Native Client 11.0 UID=bit9 Trusted_Connection=Yes DATABASE=das SERVER=<YourSQLServerNameHere>
An example with a custom port can be found here