C6300 not able to reach ipv4 sites, but only ipv6 sites

[TJEwing]

Started using my C6300 at a new home with Xfinity/Comcast cable in May 2017.  About two days ago (mid-September 2017), we couldn't reach most sites and received 'server can not be found' or 'internet not reachable' errors to ipv4 sites.  We can reach the big ipv6 sites like Google, Facebook, Youtube, via both wifi and directly connected with ethernet to modem.  I called Xfinity and rebooted modem multiple times, to no avail.  Xfinity rep stated it could be a firmware change from Netgear (although from i read online, Xfinity/Comcast controls the firmware updates of the netgear modems?).  I can see ipv6 address, but no ipv4 router address in my wifi settings.  And when i test my ip address on the one website i can reach (http://whatismyipaddress.com/ds-check), it shows an ipv6 address, but ipv4 is "not detected." Xfinity stated i should test one of their modems, or have technician come out to test one (for a fee).  The other solution offered was to try a factory reset on my modem.  Any insight out there on why after months of working fine, ipv4 sites can no longer be reached?

Thanks TJ

[TJEwing · Accepted solution]

Hi, I tried a hard reset of my modem back to factory settings, which worked. I had to resetup my wifi network, but a small price to pay for working internet. Good luck
Tj

[DarrenM]

Hello TJEwing

Have you tried to access the web page using a IPv4 Ip address in your web browser could be a DNS issue.

DarrenM

[Alavoie1992]

We are having the same issue!

Comcast/xfinity was unable to help us out.

Hopeing to have this fixed soon, I take 4 classes online and run a small business no internet access from my computers or tablets is really impacting everything.

[TJEwing · Accepted solution]

Hi, I tried a hard reset of my modem back to factory settings, which worked. I had to resetup my wifi network, but a small price to pay for working internet. Good luck
Tj

[BaxterB23]

Hey there, it seems a few people have experienced this issue over the last couple of days. I too have the C6300 and Xfinity and Xfinity said everything is fine on their end.
I can't access netgear routerlogin.net because of the issue. How did you factory reset the modem/router? I tried a safety pin on the Reset button on the back but it just rebooted the device with all the same wifi networks etc

[DarrenM]

You will need to hold the reset button for 10+ seconds to do a factory reset.

DarrenM