Hi Surya,
Fast Data Masker (FDM) supports DB2 AS400: Fast Data Masker System Requirements - CA Test Data Manager - 3.5 - CA Technologies Documentation
Here is more information on using FDM with iSeries DB2/400: Work with Fast Data Masker in iSeries (DB2/400) - CA Test Data Manager - 3.5 - CA Technologies Documentation
In reference to your connectivity question, DB2 Connect will need to be configured to allow FDM to connect using a JDBC driver. Connection this way is no more complex for FDM than for any Java application connecting to DB2 AS400. DB2 Connect is an IBM product, so questions regarding the complexity of its configuration might be better addressed by IBM. If you have any other specific questions around this, we would be happy to look into it.
As of right now, we are not aware of any limitations to using FDM against DB2/400 as compared to any other DBMS. If you have any specific concerns you would like us to address, please let us know.
I hope we have answered your questions around this. Please mark the question as 'Answered' if we have.
Best regards,
Taylor