Network address Translation
I require a little help figuring out how to handle the network address translation on the network we are installing our GTM.
Our GTM is in our DMZ, and only handles DNS queries from the internet. All of our hosts that are accessible from the internet using an external routable IP address, and the NAT is handled by our firewall.
If we configure a Virtual server on the GTM which IP address should we use? The internal IP address or the external routable IP address?
If we use the external IP address for the Virtual server the DNS response from the GTM to client is correct but the GTM can't monitor the Virtual server because our firewall can't allow traffic to enter and exit the same interface.
If we use the internal IP address for the Virtual server the DNS response is incorrect, because it returns the internal non-routable IP address but the monitoring works on the GTM.
I'm sure we are not the first company with this setup but I can't figure out how we configure the GTM to provide the correct external routable IP address from DNS queries and allow the virtual server to be monitored.