A smarter/braver-than-I RackForms user shared with me his steps to connect to a MSSQL database through a Linux box via FreeTDS. if you need to do the same this will be a huge time-saver!

>> Linux Box Setup

First set things up as a System DSN by adding the following to the odbc.ini in the /etc directory:

[ODBC Data Sources]
odbc.ini = FreeTDS

[Default]
Driver = /usr/lib/odbc/libtdsodbc.so

[odbc.ini]
Driver = /usr/lib/odbc/libtdsodbc.so
Description = FreeTDS
Trace = Yes
TraceFile = /tmp/sql.log
Servername = ODBC
Database = StormNet

>> Modify /etc/freetds

[ODBC]
host = 10.30.2.36
port = 1443
tds version = 7.2

Note: The above is added to the very bottom of the file below the examples that are already there.

>> RackForms Data Source Settings

Back in RackForms then we need to select ODBC - Generic from the DB Vendor list, and also make sure to set the DB DSN as /etc/odbc.ini. Of course we'll also need to set the proper database host values.