How to Delegate ?

[Randy Hislop]

I have two class C's.....    aaa.bbb.ccc.0   which has the corporate DNS
machine.
    and - - - - - - - - - - - -xxx.yyy.zzz.0   which has no DNS machine.
The class C's are visible on the internet and are in different cities.
I need to do DNS and reverse DNS for the xxx.yyy.zzz domain
aaa.bbb.ccc.0 = thisdomain.com
xxx.yyy.zzz.0 = city1.thisdomain.com

The city1 domain is full of win95 machines and one Linux box which is their
mail server.

In order to do reverse DNS for the city1 domain I understand I must
"delegate" somehow?
What entries must I have in named.conf and athe zone files?  I have tried
the folowing without success:
named.conf
- - - - - - - -
zone "zzz.yyy.xxx.in-addr.arpa" {
        type master;
        file "city1.rev.db";
};

city1.rev.db
- - - - - - - -
zzz.yyy.xxx.in-addr.arpa.  IN  SOA   thisdomain.com.
rhislop.edm.thisdomain.com. (
                                        20000818        ; Serial
                                        10800   ; Refresh after 3 hours
                                        3600    ; Retry after 1 hour
                                        1209600 ; Expire after 2 weeks
                                        172800  ; Minimum 2 days
                                )
zzz.yyy.xxx.in-addr.arpa.       IN      NS      edm.thisdomain.com
99                             IN      PTR
herismann.city1.thisdomain.com.
102                           IN      PTR     jorourke.city1.thisdomain.com.