When using CSS as a dns server, is it possible for it to resolve a domain name to a private address when requests are coming from inside network? Alternatively it would also have to resolve the same domain name to the public address for external clients. Is this possible? thanks.
If there is a firewall delimiting the inside and outside, it is up to the firewall to catch the dns response and perform the change public->private or private->public.
All Cisco firewalls are able to do this.
This is called dns fixing.