I recently attempted to upgrade my cable modem from a Netgear C6900 combination modem/wireless router to a Netgear CM1100 modem with no router.  Initially I had configured by Deco M5 whole home system using the C6900 with the wireless router disabled so the unit was serving only in the modem capacity.  This configuration worked just fine but the reason for upgrading to the CM1100 was to be able to have access to faster speeds in the future.  The CM1100 is capable of managing Gigabit internet speeds while the C6900 is not.

The new modem install was accomplished without incident and it was activated and working just fine as I was able to access the internet via ethernet connection to my desktop.

I attached the Deco M5 to the system and attempted to set up the whole home network.  This is where the problem began.  The M5 (main) initiated correctly and set up the network using the specified name but when the M5 attempted to connect to the network I received notification on my android phone that the network was connected but there was no internet.  Looking at the WiFi settings on the Android it indicated that the phone was connected to the network but there was no internet.

I reset the M5 to default and again attempted to establish a wireless network but I got the same results.

I then attempted to set up the M5 network by connecting the M5 directly to the Modem LAN port and obtained the same results.  The set up proceeded correctly until the stage where the M5 is connecting to the network as indicated on the phone but reported no internet service.

I chatted with a TP-Link technical support person but that became frustrating so I decided to remove the CM1100 and reinstall the C6900 that I had previously removed.  Once the C6900 was reinstalled I was able to reestablish connection to the M5 network without any problems.

One other thing I attempted using the CM1100 modem was to reset all the M5 pucks and rename my network to something totally different than the previous so it would appear this install was a clean install, but I got similar results.  Connected,No Internet.

Has anyone had a similar issue like this and does anyone have any suggestions on how to proceed.  Also is this a Netgear issue and I should reachout to them or is it a Deco M5 matter.

Thanks for all the feedback.