Device: Netgear R6220 Firmware: 20.02 snapshot r18400-f9782f5bcd
After the router has been up a while it will start to lose wan connectivity to my ISP (Frontier FiOS). I'm unable to ping the default gateway. Using my cellular data, I ssh to a remote server and ping the same gateway and it pings fine.
It's only down for a a few to 30 seconds and comes backup usually with the following message
Dec 30 01:07:02 gateway dnsmasq: possible DNS-rebind attack detected: dns.msftncsi.com
There is no indication that the wan connection is down, and the lights don't change.
The ISP sent me a new router which I have now connected up and it's been stable.
I've tried two different R6220 routers, since I have a spare, and that gave the same issues.