Hello, I just acquired a Mac Pro as a replacement for my PC DAW, so this is my first Mac. Everything has been great so far, but I find one thing rather curious and just need a bit of more experienced guidance. I'm trying to find out if I can use the second ethernet port of the Mac Pro to share it's internet connection directly to a PC or at least to share files between the two machines. It seems easy enough via the Sharing preference, under Internet & Network, but doesn't seem to work for me. I have an NIC on the PC. Is this possible with this setup? Sorry if this isn't using technically accurate terms, I'm still learning. 
If this is not what these connections are for, can anyone explain what their purpose actually is outside of complex bridging schemes that are beyond me? Sorry if this has been asked and solved before, you have my apologies, if so.
Thanks for any help.
If this is not what these connections are for, can anyone explain what their purpose actually is outside of complex bridging schemes that are beyond me? Sorry if this has been asked and solved before, you have my apologies, if so.
Thanks for any help.