Hi Marc,
Yes, you do need to configure MONyog to able access it. Open MONyog's interface, in the 'List of Servers' page click on 'Register a new server' (or edit an existing registration). In the page that appears next select 'SSH Server Details' on the left and fill in the details. I would've given you a screen-shot of it, but for some reason the forum software isn't letting me upload the image. So do come back here if you're unable to get it working… by that time I'm sure the sys admin would have that fixed.
You wouldn't need to configure a port specifically for MONyog. Since SSH by default runs on port 22, you can just fill that in while editing server details.