[CentOS] simple DNS question - reverse nslookup fails.

Hello all,

I am trying to configure a subdomain DNS server on a Cent OS 5.1 - for
my lab.  Brief configuration:

Lab machine ---> 192.168.17.2 (should respond to DNS queries from
hosts in 192.168.16.0/20 network)

1.  I would also like to forward any queries outside the above network
to our corporate domain (no firewalls between our 192.168.16.x network
and the corporate network.  The domain server is:  dns.company.com
with an IP of 10.100.1.2 (255.255.255.0).

2.  What I have configured is:

192.168.17.2 --> myhost.lab.company.com
10.100.1.2 -->  dns.company.com

3.  Installed the dns bind 9 in myhost and set basic configuration via
the system-config-bind GUI.  My configuration file specific to my
setup there is:

 cat lab.maxiscale.com.db
$TTL 1H
@       SOA     myhost.lab.company.com.
root.myhost.lab.company.com. (       2
                                                3H
                                                1H
                                                1W
                                                1H )
        NS      myhost.lab.company.com.
qaserver2 A       192.168.17.3
qaserver1 A       192.168.17.1
myhost A       192.168.17.2

=================

The rest of the DNS/Bind records were based upon the auto-generated
files from the Bind GUI Config tool.

3.  I also changed myhost's resolv.conf to reflect the following:

search lab.mycompany.com
192.168.17.2
search mycompany.com
10.100.1.2

======

PROBLEM:

1.  When I am in myhost.com, I can perform:
a.  nslookup hostname (to any host within 192.168.x and 10.100.x networks)
b.  nslookup ip to anyhost wtihin both networks.

2.  When I am in one of the hosts within 192.168.x aside from
myhost.com (for example, qaserver1 or qaserver2):

a: SUCCESS to nslookup hostname to any host within BOTH networks.
b.  FAILS to nslookup ip (reverse nslookup) to anyhost within the
10.100.x network.

this is the error I get:

nslookup 10.100.1.2
Server:         192.168.17.2
Address:        192.168.17.2#53

Non-authoritative answer:
24.1.100.10.in-addr.arpa        name = dns.company.com.

Authoritative answers can be found from:
.       nameserver = e.root-servers.net.
.       nameserver = f.root-servers.net.
.       nameserver = g.root-servers.net.
.       nameserver = h.root-servers.net.
.       nameserver = i.root-servers.net.
.       nameserver = j.root-servers.net.
.       nameserver = k.root-servers.net.
.       nameserver = l.root-servers.net.
.       nameserver = m.root-servers.net.
.       nameserver = a.root-servers.net.
.       nameserver = b.root-servers.net.
.       nameserver = c.root-servers.net.
.       nameserver = d.root-servers.net.
a.root-servers.net      internet address = 198.41.0.4
b.root-servers.net      internet address = 192.228.79.201
c.root-servers.net      internet address = 192.33.4.12
d.root-servers.net      internet address = 128.8.10.90
e.root-servers.net      internet address = 192.203.230.10
f.root-servers.net      internet address = 192.5.5.241
g.root-servers.net      internet address = 192.112.36.4
h.root-servers.net      internet address = 128.63.2.53
i.root-servers.net      internet address = 192.36.148.17
j.root-servers.net      internet address = 192.58.128.30
k.root-servers.net      internet address = 193.0.14.129
k.root-servers.net      has AAAA address 2001:7fd::1
l.root-servers.net      internet address = 199.7.83.42

=====

I must be missing something stupid and apparent .... any help would be
greatly appreciated!!!

:)

thanks in advance!


-- 
best,

Vince