Ok, good, your static ip devices need to be outside the dhcp assignments.
Google that modems model and "bridge mode password" & "twc" ... someone should have found it
NYC was doing a password of the week, maybe other places as well
There's also the super user & password, the one with the numbers in place of vowels...
Did you ever get this to work? I have an Aiport Express I'd like to connect to the DG860A modem, but I have not due to it looking like it doesn't work. Any advice/tips are appreciated. Did you have to call TWC to get the Arris in bridge mode?
To all those that still have this problem, (i know this is two years old) once you type in 192.168.100.1 and get the page that was in the posted snapshot click on wireless, it will take you to the modem's login page where you can put in the username and password. For most of twc's arris modems its admin and password. If that doesn't work try 192.168.100.1:8080 in the address bar. Good luck!