i am using red hat ipchains to set up a firewall. Since the internal machines need to use internal internet service, i have set up a internal DNS
for local network and a external DNS for outside network. Both are using linux red hat. It works
fine. Both outside and inside machines can access my internal internet service using domain name.
But if a new internet service machine is added outside the firewall, i need to configure both external and internal DNS since if I don't add
it to the internal DNS, the machines inside the firewall can't query the IP of the new machine.
I feel very troublesome every time the IP is changed or a new machine is added outside firewall. I need to change both DNS.
Is there anyway that if a domain name can't be queried by the internal DNS, the request can be forwarded to external DNS automatically? If so, i can just change the external DNS. Also, internal machines can access the both internet service inside and outside the firewall without changing the config of internal DNS
or any other suggestions?