The NAT on my router is using NAT/ALG. This NAT process actually changes the DNS payload IP to an IP address that is mapped to an external interface.
Basically when you enter the ip address 192.168.1.21 for the www entry in your DNS, the NAT on the router changes DNS IP Address sent to your outside interface. But when you change the IP address for www in your DNS to a 65.x.x.x number the NAT can't map it to an outside interface so it just drops the packet.
Is there any way to work around this as I'm trying to send people visiting one of my sites to a server outside my netork and only have the server inside my network to work as a backup?