If you need to reset back to default the camera IP configuration (IP address, gateway, and the DNS server) of a CM4x or CM7x, press on the IR remote control the following button combination:

[*] → [＃] → [Manual]  

(Press STAR(*), release, then POUND(#), release, and then press MANUAL. Do not press all buttons at the same time!) 

As confirmed in the user manual:

Please note that same command will also reset the admin username and password but not the user1 and user2 credentials

* The default IP address of the CM4x and CM7x series is 192.168.5.163