Troubleshooting step is to reboot both the cable modem (or optical network terminal for those lucky to have an optical fiber connection) and the router. Also, ensure that all Ethernet cables are completely connected with clips situated, connecting both the router and modem together. Furthermore, check that the suitable ports are used, for example, that the Ethernet cable from the modem goes into the WAN port of the router.
Make sure to finish the other troubleshooting basics, including ensuring that your modem still has a signal from your ISP. On the off chance that this checks out, you should also know how to change your routers settings, update its firmware, and reset it if require be. Underneath, we have detailed how to do that for some prevalent router manufacturers.