C6300 connects to WiFi but no internet access

[Ctiz]

I have an ac1750 WiFi Cable Modem router model c6300. I have had it around a year and it has worked fine up to now.
We recently went on a trip, and I unplugged the modem while we were gone. Yesterday when we returned it seemed to work fine for a couple hours then I lost signal. I could still connect to the WiFi but got no internet access. I power cycled The modem and nothing changed, and went to bed figuring it was an issue with my ISP.
When I got up this morning, nothing had changed. I noticed that all of the lights were lit normally on the router as though it were working fine. I called Spectrum/Time Warner and he did several tests and a rebooted the modem and said everything appeared normal from their side.
It has now been over 24 hours and nothing has changed--connect to WiFi as normal but no internet connection even though the hardware indicates that everything is normal.

I have tried doing several factory resets, fiddled with settings, changing names and passwords. I have connected wired and wireless from several devices and nothing seems to help.

I have found similar issues all over the forums but not very many solutions to this specific issue. Ive run out of things to try.

Thanks in advance.

[DarrenM]

Are you able to test another cable outlet in your home or remove any type of spliitter connected to the cable line between the modem and the wall plug?

DarrenM

[tgongaware]

Mine did about the same. It appears to have happened when Comcast/Xfinity rolled out the 2.01.26 Firmare to me.

The exact symptoms of mine were it would now only give out IPv6 addresses and won't give anything an IPv4 address. This broke all kinds of things. I changed most of my devices to have statically assigned IPv4 addresses and am able to continue on. Some of my devices can't be set statically, so those are just stuck without being able to connect right now.  I keep hoping they will fix whatever they did, but so far no luck there. 

[tgongaware]

I did a factory reset and it changed the gateway address from 192.168.1.1 to 192.168.0.1 (routerinfo.net) and it is now assigning IPv4 addresses again. You will have to redo all your settings after doing the factory reset.