10.11.12.1 is the frontend node, you should have no problem using ksysguard on it. For connecting to the compute nodes from the frontend, I have never had any trouble. Connecting directly to a compute node from a host that is not part of the PelicanHPC cluster may take a little work. I normally connect to the frontend, and to the compute nodes from the frontend. I don't recall ever having tried to connect directly to a compute node, so I'm not sure what steps would need to be taken. Probably you just need to copy ssh keys to appropriate places.