1 - Select the Sonar X2 standard in the Nucleus Remote (this is also compatible with Sonar X3)
2 - in ipMIDI make sure that at least 2 ipMIDI ports are enabled.
3 - Navigate to Sonar > Edit > Preferences > MIDI > Control Surfaces
4 - Press the yellow star in the top right corner of the window to add a new controller
5 - Press MIDI Devices... and ensure that Ethernet MIDI ports 1+2 are ticked for both input and output - press OK.
6 - In the Controller/Surface Settings box, add a Mackie Controller assigned to 01 Ethernet MIDI for both input and output
7 - Now add a Mackie Control XT assigned to 02 Ethernet MIDI for both input and output
Restart Sonar and you are set to go.