Newbie: Reverse lookups for secondary DNS + routing problem

Hi:

I have a PowerMac-G4 running OSX Server 10.4.10.
This machine should provide the following services to our branch office: Firewall, NAT, VPN, OD, File Server.

The main office has a MacPro providing DNS, OD Master, and VPN.

My idea is to setup the G4 as a secondary DNS and OD Replica.
This could be achieved using Apple’s provided s2svpnadmin to link two sites via an L2TP VPN.

Primary DNS: 10.100.10.10, on 255.255.255.0 network.
Secondary DNS: 10.100.20.10, on a 255.255.255.network.

I have added an entry in the primary DNS for the G4, and configured the G4 as a secondary DNS via ServerAdmin GUI.

Reverse lookups are not working. On the G4:
$ host primary.mydomain
primary.mydomain has address 10.100.10.10

$ host 10.100.10.10
Host 14.10.100.10.in-addr.arpa not found: 2(SERVFAIL)

Routing is not working either. I can not reach the internet even with IPs.

Apple supoprt has suggested that the internal interface should be configured as the main interface and WITHOUT a router address.
My guess is that it should then take the second (external) interface as the default gateway.

And so have I done. The internal NIC, default gateway, has no router address defined. I think this is weird, but it might be needed to get the OD replica using the internal address as its main address.

The second NIC, has a router address.

Note: the second NIC was added after the installation of the OS, as extra drivers were needed. I point this out because I remember some time ago I had issues with OD because the NIC has no cable connected to it during installation and thus was not recognized by some script during installation !?!.

Any hints are greatly appreciated.
Thanks in advance!