Gateway issues

couple of issues.

1) when gateway is in bridge mode I am unable to get to internet as DHSP is off and comcast has no documentation telling us how to configure conencted router. 

2) when in normal mode, there appears to be multiple subnets one "hidden" depending on the ethernet port conencted to. I connect to port 2 and I See addresses in 172.16.12.0 network. that is not deocumented in anything i see so far. my gateway is xb7. when i uncheck the box on port 2 and get an IP address from the gateway i cannot ping the gateway. 

My initial take, this gwateway is a barely better than a hub. its not very smart. it cannot do static or dynamic routing and its hard to navigate. i give it a 1 out of 5. the service seems better. 

i think ATT/VZ are missing out big time in this space. they seem to have ceded it to Comcast.  Stupid move.