CM1100 not connecting to router

[coolamundo]

Cable provider: Xfinity

What I did

• Hooked up the modem and activated it with Xfinity. Everything seems OK.
• Connected my PC to LAN1 and got a connection and 720 MB download (per fast.com)
• Disconnected the PC and connected the Nighthawk Router to LAN1. It doesn't work, as if there's no signal to the router although all of the lights and whatnot seem to indicate it's on. 
• Connected the PC to input 1 on the Nighthawk router to see if it would push a signal to the PC. Nothing.
• Since the router is new I didn't want to spend time troubleshooting it, so I tried to hook up my Google Wifi router which I know works fine. Same thing, nothing seems to reach the router connection.
• The internet works from Lan1 to my PC, but if I connect Lan1 to either of the routers..nada.
• At that point I gave up and hooked up the Xfinity modem and everything is working fine again. I have a connection to my PC and the router is working.

What should I attempt to do?

• When I get time I will do a factory reset on everything.
• Assuming I get the modem activited and a signal to my PC, what should I do to get the router set up and working? 

Any help is appreciated. Thanks.

[plemans]

For your router, are you talking the RAX80 that you reference in the signature line?

When you activated the modem and it connected to the pc, did you follow the procedure for changing devices? the modem only gets a single public IP address from your provider. it does have 2 ethernet ports but it can only be used for a single device*. 

You can also setup the RAX80 without internet to get it fully updated. Get the latest firmware on it and then factory reset it. The firmware changes were quite significant since release and this can help with setup.

Once the router is fully updated and reset and the cm110 is back activated from your isp, try this:

power off both devices, don't connect anything to either device.

power up the cm1100.  Give it a few minutes to fully boot and connect.

connect port 1 from cm1100 to RAX wan port

Power up the RAX. Give it a few minutes to fully boot.

Then try setup. Don't setup port aggregation at this time. Some of the RAX devices have had issues with wan port aggregation. 

Don't plug anything else into port 2 of the cm1100. I'd give it a bit for the firmware between the cm1100 and RAX to solidify before using wan port aggregation. For some its worked fine, others have had nothing but issues. 

*unless your isp allows more than 1 public ip address. most don't. I know xfinity doesn't for their consumer lines as I have xifnity.