Problems connecting to DB2 (Iseries)

The external party where we use the ISeries from has recently setup a VPN tunnel to 'our' Iseries. Now, of course  the old IP adress doesn't work anymore. 

after that we must use the new IP 172.16.55.1.

However this doesn't work, when I use test connection I get an error message in the log saying : 

No connection could be made because the target machine actively refused it 127.0.0.1:12003

To connect directly to this ISeries we have to execute this command : Route add 172.16.55.0 mask 255.255.255.0 172.16.0.2 –p  as an admin user but I don't know if this has to be filled in somewhere in OutSystems setup.



do I need to setup the VPN connection? See attachment. 

The external party where we use the ISeries from asks us to provide the specific portnumber which they can setup as an allowed portnumber to access our IBM Iseries. 

Could you please provide the portnumber?  

I support this is port number 12003? because the error message is : No connection could be made because the target machine actively refused it 127.0.0.1:12003