Solution (?) for Delegation of < /24 sub-domains

[Jason M Granat]

I have been searching for this for a few weeks now, read RFC 2317, read
"DNS and BIND", read the posts, read the FAQ's, scoured the net...
Seems like many people are having the same trouble with this.  Well,
after many failed attempts to duplicate what all the documentation says
we tried something different.  Maybe this method is already posted, but
if it is I never saw it, so I figured I'd share it because I know how
maddening it has been to make this work.

I don't know if this method has problems, if so I would appreciate
feedback.

Here is a sample for a class C subnetted into 4 sub-domains, each
delegated from the ISP to the clients.  No need for CNAME'ing all the
IP's.  So far we've only tried this with UNIX BIND 8.2.1 and up.
Wouldn't work with NT DNS or NT BIND 4.9.7, haven't tried with UNIX BIND

versions lower than 8.2.1

In the ISP's named.conf:

zone "0-63.100.168.192.in-addr.arpa" in {
     type slave;
     file "/var/named/db.0-63.100.168.192.in-addr.arpa";
    masters { 192.168.100.1; };
};

zone "64-127.100.168.192.in-addr.arpa" in {
     type slave;
     file "/var/named/db.64-127.100.168.192.in-addr.arpa";
    masters { 192.168.100.65; };
};

zone "128-191.100.168.192.in-addr.arpa" in {
     type slave;
     file "/var/named/db.128-191.100.168.192.in-addr.arpa";
    masters { 192.168.100.129; };
};

zone "192-255.100.168.192.in-addr.arpa" in {
     type slave;
     file "/var/named/db.192-255.100.168.192.in-addr.arpa";
    masters { 192.168.100.193; };
};

Then each in-addr.arpa sub-domain has an equivalent zone in their
named.conf:

Sub-Domain A:
zone "0-63.100.168.192.in-addr.arpa" in {
     type master;
     file "/var/named/db.0-63.100.168.192.in-addr.arpa";
};

Sub-Domain B
zone "64-127.100.168.192.in-addr.arpa" in {
     type master;
     file "/var/named/db.64-127.100.168.192.in-addr.arpa";
};

Sub-Domain C
zone "128-191.100.168.192.in-addr.arpa" in {
     type master;
     file "/var/named/db.128-191.100.168.192.in-addr.arpa";
};

Sub-Domain D
zone "192-255.100.168.192.in-addr.arpa" in {
     type master;
     file "/var/named/db.192-255.100.168.192.in-addr.arpa";
};

The db files for the sub-domains are laid out standard, like for a full
class C or larger, nothing special in them.

Again, I am not an expert and there may be reasons why nobody does it
this way.  I would really like to know any of those reasons.  It's
possible that I have just totally missed the boat and this is how
everyone's doing it, but I figured not likely, seeing all the
frustration in posts on this topic.  That being said, it is working.  We

have implemented it with our ISP and in turn with several of their
customers, so far everthing runs smoothly.

Jason