What are your settings for this Modem?
Are you using it in modem/router or modem only mode?
I also bought one of these modems and for the last two days I have been trying to get it to work. Just cannot get it to speak to the router when I connect it to the WAN Port on the ASUS RT-N66U.
It works fine in Modem/Router Mode connected straight into the PC LAN Port. But the minute I change it to Modem Only Mode and connect it up to the ASUS, it all becomes an " Unidentified Network " and will not speak to one another.
Use the old HG612 and all works as it should.