Disable auto change IP address

Most cable modems, save the ones that maybe have built in routers that default to 192.168.1.1, most other stand alone cable modems default to 192.168.100.1, this would not conflict with what NG uses as there default address of 192.168.1.1. Of course I don't use modems with routers built in so I have not had chance to experience this kind of issue. For the modems I have used, all stand alone, there isn't any kind of IP conflict in this regard with any of my routers using .0.1 or .1.1. Even if I remove the RF cable.

I presume the only issue here would be if the modem router unit uses a default or falls back to 192.168.1.1 when the RF cable is disconnected and if you have your NG router using same IP address string, then the Orbi would detect this then switch itself to a 10. something IP address pool. Correct? 

Looking at the user manual, about 2.5 years old, I see it's default is 192.168.100.1

http://www.ubeeinteractive.com/sites/default/files/file_resources/DDW36C_Subscriber_User_Guide_101016.pdf

The DDW36C is pre-configured with the default parameters for Charter Communications
(formerly Time Warner Cable).
Local Port Address: 192.168.100.1
Web Interface: http://192.168.100.1
Operation Mode: NAT Mode
Subnet Mask: 255.255.255.0

This shouldn't be a problem...