Shielded Ethernet Cable

I'm not sure that the Mac's ethernet port terminates the drain wire/shield from a shielded cat6 or cat 5/e.

I imagine one way around the issue is to terminate your run into a punchdown block or keystone connector in each room, and terminate the drain there, then run utp cat 6 patch cable to your computers.

Don't forget that you will need to terminate the drain and make sure the termination ground points are at the same potential, otherwise you will induce an unwanted current flow in the cabling.

I would suggest that if you have a real issue with a noisy environment, you consider running fiber through the noisy area, and terminate that with media converters.

Also remember that unless you are running for the entire 100 ft in parallel and close to the power wiring, you shouldn't have to much of a problem, even separation of a few feet should be sufficient for most applications.

Tom N.

http://www.webopedia.com/quick_ref/EthernetDesignations.asp
Reading through the ethernet designations you will see that there is a huge difference in the choices you have as well as there maximum distance, as well as sheilded and non-sheilded.
Cheers Don