Last week a call came in from a home office, “internet down”. A real problem if you work remotely. Restored connectivity after replacing the primary networking device. This one was different, as has two modems.
Called Comcast, learned that one device in the basement was just for phones. That meant the other modem was probably the one used for internet. Jacked directly into that modem. Did a release/renew and got on line (i.e., the house had connectivity). Suggested to owner possibility that router/firewall/wireless device had failed. Replaced that device, and regained connectivity. Got wireless devices to reacquire.
One approach when you’ve lost connectivity is “simply” in troubleshooting (not the only steps to take, as sometimes just rebooting the networking gear can do the trick). Make sure you understand your networking gear setup (i.e., are you using one device, or repeaters or WAPs etc). Jacking directly into the modem after a modem reboot, can help prove you’ve got connectivity (is the problem inside or outside the building) and narrow down whether problems are upstream or not.