Starting with v4.0 the configuration of Devices (previously known as Engines) and Channels is done within the User Interface and this process is working the same way for just:in mac and just:in linux.
The Configuration Panel for both JIM and JIL can be found within the just:in application (=User Interface) and there all Devices can be managed and therefore a central configuration for all available Devices and Channels is possible. There is no need anymore to do and check settings on each and every engine machine. The only step, which is necessary on the engine machine is to start the engine application and to know the IP-Address of this particular machine.