I upgraded my 2009 Mac Pro to ML the other day. I use an aggregated link using both gigabit NICs to an 802.3ad capable switch for speed. This worked perfectly under Lion but under ML the virtual device fails to start with each member showing "no partner" in the advanced dialogue. If I take one of the NICs out of the bonded virtual device and let it come up as a single interface, then re-add it to the virtual device everything comes up and the link aggregation works perfectly until the machine is restarted, then I have to go through the same rigmarole. I've tried this with a couple of different switches and tried changing the LACP timeouts, modes etc but always with the same result. Has any one else tried this and had any luck?