Configuring a DRAC (Dell Remote Access Card) behind NAT is surprisingly simple, yet Google fails to yield any useful results.
All that needs doing is to forward the following ports (TCP Only) to the DRAC card:
If you find that ports 80 and 443 are already mapped to an existing server, you can forward different ports (i.e. 81 and 444) however the DRAC card must be configured with these ports. You cannot forward an external port 444 to an internal port 443! The HTTP(s) ports can be changed from the Services section in the DRAC configuration menu. (Read as: System->Remote Access->Configuration->Services). I have not yet found a way of changing the last 3 ports.
It is worth noting that the last 3 ports are only required for the DRAC console. The web interface (without remote console access) is fine with just ports 80 and 443 forwarded.