How can you identify if a router is causing internet issues?

To determine if a router is causing internet issues, directly connecting a device to the modem bypasses the router entirely. This approach allows you to establish whether the internet connection is functional without the influence of the router’s configurations or potential malfunctions. If the device connects to the internet successfully while plugged into the modem, it suggests that the issue may lie within the router itself. This diagnostic step eliminates unnecessary complexities that the router could introduce and provides a clearer understanding of where the problem may exist.

The other methods, while useful for general troubleshooting, do not directly confirm the router's role in the issue. Checking the router’s lights may indicate whether it’s powered on or indicating an error status but doesn’t provide a definitive answer about the router’s ability to function correctly. Rebooting the router is often a recommended troubleshooting step, but it doesn't confirm the problem; it merely resets the device. Contacting the Internet Service Provider can provide insights regarding the connection from their end but doesn’t specifically pinpoint router-related issues.