several subzones in one db file

[James Wilde]

I feel fairly comfortable with my experience with bind and dns as a general
rule, but I have a little problem I'm not sure about involving subzones.

We are taking over a number of subzones from another ISP without taking over
the parent zone.  Let's call the parent zone isp.com.  We are taking over
post.isp.com, private.isp.com, xyz.isp.com and a bunch of others, but the
other company retains isp.com.  They are going to delegate the subzones to
us.  In fact, the subzones all point to the same mail server.

What I want to know is whether I can set up a db file isp.com on my server
for the delegated zones, and include lines like:

$ORIGIN post.isp.com
@        IN    A    123.123.123.123
$ORIGIN private.isp.com
@        IN    A    123.123.123.123
...

or whether I have to have separate db files for each subzone.

Thanks in advance.
--


mvh/regards

James