Provided you are only doing a short run, it is not external (outside the house) and not being run next to noisy power cables, cat 6 should be fine.
This is a good video to watch on subject.
I would however advise that you get a short Male to female lead and attach this to the B2 see
or
If you do this it means that you can unplug the Ethernet and move the B2 if you need to, without having to take the back off to disconnect the cable. (You plug your longer ethernet cable into the now exposed female socket) - otherwise you are draging round 10 m of cable!
Hope this helps
Fred