To setup DMZ, you first need to reserve an IP to the machine that you want to be exposed. The reason is that you do not want your DHCP server to assign a computer incorrectly as the DMZ, which can pose security problems.
Setup Static Internal IP First
Before you setup the DMZ host, make sure that you have reserved an IP for your DMZ host. If you are not sure how, please check How to Reserve Static IP for SBG6580. With the static IP for the machine that you want to set up the DMZ for, you can now finish the Motorola Surfboard SBG6580 DMZ setup.
You typically only want to use DMZ as a last resort to trouble shoot your router’s firewall errors. Use DMZ when either
Go to Advanced > DMZ Host
Input the internal IP address that you have chosen for your device. And you have successfully setup the DMZ host feature for your Motorola SBG6580!
Common DMZ Problems / Questions
Does DMZ conflict with Port Forwarding or UPnP?
The short answer is yes and no. You can have both of the features setup and they will all still work as expected. The only difference is that DMZ will successfully override the other two settings.
What DMZ does is that it will place your device outside of your router’s firewall, which renders port opening techniques useless.