I was setting up my home router to allow VPN access so I can lookup specific files on my home computer while I was out of town. It's something I've done before and is fairly simple and strait forward. With that said I haven't been able to get it to work since we had home security installed. I finally figured out why which I'll get to in a second but first I want to explain how things are setup. I have my own modem which plugs into the special home security router which then plugs into my nighthawk router. The problem is the security router. My router isn't getting the VPN request because the comcast home secuirty router is blocking it. I plugged my modem directly into my router and the VPN connection worked. What needs to be done to stop the comcast security router from messing up my home network? Can it be moved behind the nighthawk? I am very capabile setting up port forwarding, port triggering, static routes, etc. if that's what it takes. If there is a way comcast can change the settings on the security router so all non-home security traffic passes through to the nighthawk, that should work too.
If you are referring to the sidecar that is installed for you XHome system, it uses the Zigbee protocol so it shouldn't have any effect; mine never did ( I subsequently replaced it with my XB3 gateway, which supports XHome).