Orbi WiFi 7 RBE973

Re: Connection issues with CM1150V modem and AX6000 (RBK853) - both Netgear products


Connection issues with CM1150V modem and AX6000 (RBK853) - both Netgear products

I tried replacing my existing Xfinity model with a Nighthawk CM1150v and Orbi AX6000 (RBK853) tonight.  Modem worked fine, but I coule not get the Orbi to connect with the internet.  The Orbi was functioning and I could log onto it with my phone using the Orbi app.  Just showed "Offline".  I then logged onto Orbi with orbilogin.net from web browser connected to the wireless, and it showed  the Internet not connected.  I plugged the Orbi directly into the modem and still same issue.  I plugged ethernet cord into my computer to test the data worked, and it did.  So, somehow the Orbi wireless modem is not working with the CM1150V modem.


I'm about to try my old Xfinity all-in-one modem/wireless, by disabling the wireless and just using the router to see ir Orbi behaves same way when I plug into the Xfinity modem.  Does anyone know if there is a compatibility issue between the Orbi AX6000 (RBK853) and a Nighthawk CM1150V modem?  Both same company, you'd hope it's not a compatability issue.


Any advise on settings to look at between Orbi and CM1150v modem?

Model: CM1150V|DOCSIS 3.1 Nighthawk® Multi-Gig Speed Cable Modem for XFINITY® Voice
Message 1 of 6

Re: Connection issues with CM1150V modem and AX6000 (RBK853) - both Netgear products

Make sure nothing else is plugged into the cm1150v. The CM1150v has 4x ethernet ports but for xfinity only 1 port is usable (2 if you use wan port aggregation). The others are only useful if you have a business class line or pay xfinity for multiple IP addresses. 

So try this. 

power off both the cm1150v and the orbi. Unhook the coax from the cm1150v and disconnect any devices connected to both. 

connect coax back to cm1150v. Power it on. give it several minutes (up to 5).

Then connect port 1 from cm1150v to wan port on router. 

Power router on. give it several minutes again to full boot. 

then check connection on the orbi. 

Message 2 of 6

Re: Connection issues with CM1150V modem and AX6000 (RBK853) - both Netgear products

Yes, first make sure your Comcast IP address and internet connection is working with your new modem (connect a laptop or PC directly to the modem by ethernet).  Then you can migrate that internet connection to your Orbi and start using its wireless network.


Comcast IP addresses are finicky when you replace their modem with new equipment, as you are doing.  It also doesn't like it when you change the device (MAC address) receiving the IP address, like you will do when you switch from the laptop->modem to Orbi->modem.  Each time you can call 800-COMCAST and use the automated system to reset the modem or else go to https://customer.xfinity.com/#/services/internet and click the Restart Modem link (this works with their modem, don't know if it works the same if you use your own modem like the CM1150V).

Message 3 of 6

Re: Connection issues with CM1150V modem and AX6000 (RBK853) - both Netgear products

I just went through this tonight

The cm1150v has 4 Ethernet ports but with xfinity residential service, only one is active.

If you plug in only the Orbi- it works fine
If you plug in a laptop first that will work and the second item not

The workaround is to only plug in the orbi, and for any other wired connection in the house, use the Ethernet jacks on the orbi

I rebooted , and restarted things and changed settings on the orbi until I realized the issue. A plain vanilla orbi setup should work fine
Message 4 of 6

Re: Connection issues with CM1150V modem and AX6000 (RBK853) - both Netgear products

Thanks everyone for your responses.  After several tries and much research, I learned that while the CM1150v has 4 ports, Comcase only releases one IP address to home plans.  Therefore, the other three ports are inactive.  I rebooted modem as suggested with nothing plugged in, then plugged in my laptop to port 1 to make sure modem was activated.  Once I was sure the modem was activated and able to access internet with the port 1, I unplugged the laptop and plugged in my ORBI.  Unfortunately things didn't work.  After an hour with NetGear support, they had me do a factory reset on the Orbi and re-install connected to the active port.  This we did with a combination of logging in with laptop now connected via ethernet through the ORBI using Orbilogin.net, and the Orbi iPhone app.  After successfully reinstalling the ORBI, it worked fine.  Have it now running and operating successfully.  Only one hiccuo, the next morning my internet was not working because Xfinity chose to deactivate my modem.  I had to reactivate the modem by unplugging the ORBI, plugging in my laptop to port 1 on the modem and reactivating it.  Turns out that Xfinity activation didn't complete my voice service activation the first time.  They thought it was still active on the old modem of theirs and switched everything back over to their old modem that was not even hooked up.  Two hours later and multiple customer service calls to Comcast, I got the activation to the new modem completed thoroughly and their records updated to my new CV1150V.  Hooked back up the ORBI to port 1 and everything is once again working like a charm.


Hoping no more hiccups.  But thanks for all the help.  This one was not a simple install.  But, in the end, I'm quite pleased with the ORBI performance.  Like night an day compared to what Xfinity had me using (which was supposedly their best).  Gonna keep the rented router for another week to make sure things go well with this new configuration (CM1150V modem and ORBI AX6000/RBK853).  Just got printers in the house working again on the network and a second switch I have for all the media room equipment.


Good to know this is an active community with such strong netrowk backgrounds.


Thanks again! 

Message 5 of 6

Re: Connection issues with CM1150V modem and AX6000 (RBK853) - both Netgear products

Just because the modem has additional ports doesn't mean it's got a router built in. Just be aware that any NG CM series modem with two or more ports does not have a built in router. Only the C series modems has build in router. 


It's up to ISPs to control what IP addresses they assigned or allow on these modems with two or more WAN ports. Most only assigned 1 IP address per modem regardless of how many ports are on the back. 


Generally just a power cycle (30 sec) of the modem and the connected device, i.e. PC or router is all thats needed to get them connected if the modem has been activated fully and correctly. 

Message 6 of 6
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