I recently swapped a router out for an old one to check an internet problem (to rule it out basically) and when I tried swapping the newer (better) one back in it networks fine (ie computers can see/stream off each other) but it doesnt recognize as being plugged into the internet.
After doing a factory reset via routerlogin.net I still have the same problem. The only thing I can think of is maybe the port got damaged? (The ethernet cables all work fine).
My process for hooking up the new router in case I was doing something wrong:
Unplug cable modem power, swap all the cords, on router while cable modem was rebooting and then once modem connected I turn on router. Did I need to restart the PC as well? Is that why this is screwing up? It doesn't make any sense
Does the cable modem RJ45 port or the router WAN port appear damaged -- like one of the small copper wires bent or broken? And the cable is known to work that goes from the modem to the WAN port of the router, like tested with a machine to LAN port and can see the network?
If you attach a computer the an LAN port and enter the router configuration page for the Internet connection information do you see an outside IP address of your provider?
If you directly connect a computer to the modem, and the computer is set to automatically obtain an IP address, does it connect? You need an OS restart or an ipconfig /release and then ipconfig /renew to get the new address.