Question Regarding Restricting Updates

[Smith, William E. (Bill), Jr.]

Is it possible to restrict updates for a subnet within a particular domain
to within that subnet only?  For example, if we have domain x.y.edu for
which subnets 10, 20, and 30 are part of, can you restrict dynamic updates
on subnet 30 to only machines within that subnet?   Currently, I only see
being able to restrict updates within a domain to specific subnets but
anyone within those subnets being able to update any of the other subnet's
objects.  The background behind this question is with regards to W2K and
their "feature" of being able to overwrite existing DNS entries if you have
DDNS configured on the box.  This is according at least to the 4th Edition
DNS & BIND.  We're trying to steer away from W2K DNS and stick with our BIND
servers but want to allow dynamic updates to occur..to at least the
subdomains

Thanks,

Bill