While I can type in both qwerty and dvorak keyboard layouts, I found during my CCNA exam that I wasn't as comfortable with qwerty during the virtual lab questions. So for my next exam I have asked a couple of places about using a dvorak layout and so far one has said no with no reason given. I have asked for reason.
I can't see why it wouldn't be acceptable . I can't see why it would be difficult, since we all use different keyboard layouts around the world, and dvorak is included as standard on all windows platforms that I know of.
Has anyone been able to arrange to use a dvorak layout in exams?