[Zope] How do you Restrict ZServer socket connections

[jon@totient.demon.co.uk]

Hi 

I've followed anser's How To on "Apache and ZServer (NOt CGI)"
and now I have Zope served thru Apache via module ModProxy and the
SiteAccess Zope Product.

Fine, But Now I want to make Zserver only accept connections from
a set of known IP address (ie that where my apache server runs)

Any ideas how you do this? I can see there are options to say
which ports it listens on but no mention of restricting the
IP addresses it allows to connect.

Thanks

Jon