Looking for good solution to connect two vapp networks (same vapp)

I am looking for suggestions on how to connect two vapp networks...  Hopefully using VMware VCD operations rather than building myself.

VApp layout for this example

VM-A on vapp:network1 [192.168.2.0/24] (uplinked to masternetwork)

VM-B on vapp:network2 [192.168.3.0/24] (uplinked to masternetwork)

I would like system VM-A to be able to talk to VM-B ON 192.168.3.? (as the masternetwork link is done via VSE devices - one per uplinked in 1.5)

I could add a linux box in the mix that connects to vapp:network1 and vapp:network2 -- but seems like it would be odd to get working that way (would need static routes on VM-A and VM-B to make work) -- I am trying to find something more generic.

Anyone have ideas?  If a linux gateway appliance is needed, anyone know a small easy to setup one  (and I am hoping small - as I might need 100's of these)

Thanks!