The state of resolv.conf

[Bruno Wolff III]

On Tue, Sep 16, 2008 at 17:32:31 +0200,
  Nils Philippsen <nils at redhat.com> wrote:
> 
> I would want to be able to do that based on domain names (which is
> easily done with BIND) and on classless IP ranges. I don't think the
> latter can be done as the IP ranges are octet-granular, e.g.
> 10.in-addr.arpa for 10.0.0.0/8 -- I can't imagine how I would tell BIND
> to use a certain server for e.g. 10.1.0.0/12 (where 4 MSB of the second
> octet are part of the network address and the remaining 4 LSB are part
> of the host address).

You do it using 16 entries for the 16 /16s. In the worst case you need 128
entries.