On Mon, 25 Jun 2007, Marc Perkel wrote:
> What would be the method of detecting the domain part of a host address?
> For example:
>
> 82-46-151-246.cable.ubr04.perr.blueyonder.co.uk
>
> How would you write an ACL that would extract the blueyonder.co.uk part?
I think the point several people have tried to make is that you can't in
general do this kind of thing without knowing something about the
DNS domains and zones. Can you guess by inspection what the "domain" (in
your meaning, I'm not quite sure exactly what that is, I think you might
mean zone, but maybe not) is for these names:
mx.cam.ac.uk
virgo.cus.cam.ac.uk
ewe.damtp.cam.ac.uk
www.cl.cam.ac.uk
Hint: these are in 3 different DNS zones.
Exim does provide you with the means of looking up the nameservers for
the bottom zone of any domain name. But it doesn't tell you the name of
the zone.
http://www.exim.org/exim-html-current/doc/html/spec_html/ch09.html#SECID66
--
Philip Hazel University of Cambridge Computing Service
Get the Exim 4 book: http://www.uit.co.uk/exim-book
