This morning my internet service was down, but my Cisco DPC3848V was up, showed everything normal. Good WAN IP address, lights all green. I used the ping test tool built into the Cisco, and it reported success pinging remote sites, no failures to respond. But my computer could not ping those same sites via the Cisco (timeout).
My connected computer had a good LAN address, and could access the Cisco web browser interface and other devices on the LAN normally. I tried changing the DNS in the Cisco to Google DNS in case there was some problem with Shaw's DNS, although that shouldn't affect pinging an IP address - but it had no effect. For some reason traffic just wasn't getting through from my LAN to the WAN side of the Cisco router, but the Cisco router thought everything was normal and could still ping internet sites itself. In the end I rebooted the Cisco, and it came up normally and the problem was fixed.
Has anyone ever encountered a problem like that?