My friend was showing me his network setup the other day which is serious overkill (I'll explain below), but I was wondering if there are issues using Macs (for example the Mac mini) that are not earthed/grounded on a network that is shielded and grounded? His setup (roughly): Cat6a shielded twisted pair (STP) throughout the network. It is earthed/grounded at the server cabinet to the main earth for the the house. In Australia we have an earth rod cause we use 240 volts. Patch panel, 24 port switch etc is earthed and all internal (i.e. hardwired in the house) cat6a cables have the drain wire attached. He uses cat6a patch cables from the wall socket to the Macs as well. So basically it is a complete cat6a STP network with all the STP ethernet cable earthed through the main house earth point. His view was to make it 10 Gigabit ready. He had it installed so while he knows how to show it off, he does't really understand the questions I have set out below. The question is this, based on the above network, is it an issue using earthed STP (and rest of network) on a Mac mini or rMBP (which he has)? They are not earthed like standard PCs are (in my country (Australia)). I was guessing this is not an issue but I pointed out to him that Macs are not earthed. Second question: Can he use standard UTP Cat6 (non-shielded and non-grounded) from the wall socket even though his main network is fully STP grounded? I am guessing the answers to the above are that is is ok to use non-earthed Macs (and PCs (e.g. laptop on battery) on a fully grounded STP network and that it is also ok to have UTP for the wall-to-mac cable, but I was just wondering if there are risks or is it totally ok. You would think this super modern 10 Gigabit standard would allow for non-earthed computers and cables to be used on it, but if not then he is in trouble. Thanks for any comments.