Hi, I'll mount my rb2011 in a indoor wall-mounted rack, powering it with its adapter, and I'll use shielded ethernet cables.

I've noticed the grounding screw on the rear side, but I've not read anything about it (only about grounding antennas)
Do I need to connect a grounding cable there? Just a couple of nuts and bolts are ok?

Thank you

IMHO yes but diameter of the grounding wire should be the same or bigger than live cable has (I assume that both cables are made of the same material eg. Cu, Al etc).