Resolving Why is My DLink Router Not Connecting To The Internet requires reviewing the device’s connections and modem status. Confirm that all cables are secure, restart both devices, and verify the router’s WAN settings through the login page by using http://dlinkrouter.local. A firmware update or factory reset may be necessary to restore proper connectivity and stable network performance.
https://www.dlinkroutlocl.com/diagnosing-and-fixing-why-my-dlink-router-is-not-connecting-to-the-internet/