If you have a Palm, there is a handy app that does a lot of the necessary math for you. IPCalc http://www.ajw.com/ipcalc.htm CJK On Wed, 2002-10-30 at 09:53, Jaimie Livingston wrote: > Before I go a-googling.... > Anyone have a recommendation for a good online reference on doing binary > math? > Particularly in relation to subnetting... > > Jaimie