I can now use fixed domain names to access my home cameras without having to use DDNS, and I can use my internal Router's web-based interface to configure the port forwarding, and the speed is very fast ( shows more than 600 Mbits/s download even though I'm on the 150 Mbit/s service). I also disabled Wi-Fi on the Arris box to be sure that nobody accesses it directly, and I directly Ethernet-connected the Ethernet port of the Arris box to the WAN port of my internal router. So I set the WAN port of my internal Router to have a fixed IP address (such as 10.0.0.2 to be on the same sub-net as the 10.0.0.1 of the Arris modem) and enabled the Arris DMZ feature, specifying the DMZ host to have IP address 10.0.0.2. The FQDN is only correct when the Arris modem is in 'normal' (not Bridge) mode, so I was back to having the problem that port forwarding doesn't work on the Arris modem.

The bizarre problem is that when in Bridge mode the WAN-side IP address of the Arris modem gets assigned an incorrect FQDN. So I figured I'd just set the Arris to Bridge mode and use my own Wi-Fi Access Point / Router to do the port forwarding. I didn't want to figure out or deal with. And the unexplained 'features' (prefer private connections, advanced security) and annoying App notifications are all. But I recently changed from a Hitron cable modem to the Arris TG4482A / XB7 which has the ridiculous stupidity that you can only configure port forwarding using the App, and worse than that, instead of this working it would either give me an error message to try later, or would not let me specify the IP address of the internal destination device. I have used the fixed fully-qualified domain name feature that only Rogers offers for many years so I can access devices in my home without having to use DDNS.

Cm mac arris