Can't access DPC3939b UI

I was changing the DPC's private lan IP to 192.168.100.1 so it wouldn't be in the 10 range (as I use the 10 range behind me router and still want to be able to access the DPC's UI and avoid possible overlap of address space.

well now the DPC UI is unreachable.

I did a "show IP arp gi 0/0" on my router and it shows a 192.168.100.1 MAC/IP resolution but I just get time outs if I try to ping it.

I even connected my computer directly to the DPC and still can't get it to reply to a ping, though when I connected my computer directly my computer did get a DHCP IP and in the lease info it showed 192.168.100.1 as the DHCP server and gateway but still couldn't access the UI or ping it.

I did try the DPC's public lan side IP and that did bring up the UI but when reaching it that way it won't accept the cusadmin login so still a no go.

Also I want the "xfinitywifi" turned off.

hopefully someone can help.