I downvoted this post because ms sql server doesn't follow traditional port assignment and generally uses dynamically assigned ports.
this is directly from splunk troubleshooting:
" many microsoft sql servers use dynamic ports instead of tcp/1433. work with your database administrator to identify the correct port, or see "verifying the port configuration of an instance of sql server" on the microsoft website."
DBX2 is not able to use a non-SQL account for MS-SQL at this time, unless one of these workarounds is effective for you: http://docs.splunk.com/Documentation/DBX/2.0.2/DeployDBX/Troubleshooting#Cannot_connect_to_Microsoft...
Appears to be multiple issues on my side... I'm connecting to multiple MSSQL DBs with either a local DB account or an AD account that's been provisioned access to the database. Downgrading from sqljdbc41.jar to sqljdbc4.jar fixed my issue connecting to a MSSQL DB with a local DB account.
However, I still get an error trying to connect to a MSSQL DB using AD credentials. I've attempted multiple databases with various AD accounts.
[WARNING] [health.py] com.microsoft.sqlserver.jdbc.SQLServerException:Login failed for user 'domain\user'