01-17-15: Mcanaday10/100/1000 is a common designation for a router capable of gigabit speeds (i.e., 1000 megabits per second). If there is no indication on the router as to whether it is a 10/100 or 10/100/1000 type, Googling its make and model number plus the word "specifications" should lead you to the answer.
Will the router say 10/100 on it? And what is the designation for a router that is adequate for gigabit?
100 mbps is plenty for audio purposes, though. And if the router is 10/100 you can always upgrade it at a later time if gigabit speeds become desirable for other reasons.
BTW, I would not rule out the possibility that there could be at least slight sonic differences between interfacing to the Auralic at 100 mbps and at 1000 mbps, due to differences in coupling of digital noise to points in the system that are downstream of the ethernet interface. But if so, I doubt that which speed would be better in that respect can be predicted.
As for the extra cable, so just having something there unconnected does not affect the functioning of the lines to stereo, tv etc?I'd be very surprised if having an unused cable connected to its own port on the router or network switch would have any effect on the others. Even if it did, though, perhaps as a consequence of poor design of the router or network switch, you could of course simply disconnect it.
Best,
-- Al