[Zope] Restricting access via IP address?

I'm moving up the learning curve with Zope and have skimmed the archives of this list and other documentation so forgive me if the answer to this question is blindingly obvious (because I've got a feeling I'm missing something fundamental here) but .... .... how do I limit visibility of Zope-served pages by IP address? I guess using an if tag and REMOTE_ADDR is one of of doing it but it seems sort of kludgey when Zope seems to have most of the intranet-type bases covered. Many TIAs Paul Browning -- The Library, Tyndall Avenue, Univ. of Bristol, Bristol, BS8 1TJ, UK E-mail: paul.browning@bris.ac.uk URL: http://www.bris.ac.uk/