I would try powering all down al devices including modem and router and then back up one at a time and if that did not work then I would reset the router to factory settings and re-enter all of the settings.

Done as you suggested, in reboot modem first then router. 

 

No luck,

 

did a factory reset and same no luck. 

When you switched ports, did the same ports work or did the same devices work? If the same devices work, then try new ethernet cables for the failing devices. If it is the same ports on the router then power off the router, remove the cables and ensure the ethernet connector on the router is not damaged. Although rare, it could be the router.

@Dipps 

 

Per Archer C8 said, is it the same deivce work or the same ports work?

 

For the failing devices, have you ever setup static IP for them？ With your computer connected to the C5400 by wired cable, are you able to access internet from the 4 ethernet ports?

 

If some ports failed, please click here to get the IP and gateway of your computer; and try to ping the gateway of the C5400.

 

Besides, you can reset the Archer C3150 and these devices to give it a shot.

 

Any updates, please let us know.