If you forget the administration password, then there is little choice but to reset the router back to its factory settings. For a home router, there is often a small concealed button that initiates the reset process. Some home routers use a different mechanism. I have a router that merely needs a straight Ethernet cable connecting between its WAN port and any one of its PC/LAN ports as it powers up that triggers the reset. For commercial routers, the process of resetting the settings may require a diagnostic terminal to be connected to a special socket on the router to reconfigure it. Generally, if the router is not physically accessible, then the only way of resetting it remotely is to connect to it with a valid password and action the reset through the appropriate feature in its configuration pages. Otherwise, you must go to the router to work the reset.
There is a difference between resetting a router and rebooting a router. When you reboot your router that means you cycle the power to it. Resetting your router involves changing it back to its factory settings. If you have forgotten the password to your router and now you want to reset the password. First, you need to reset the router back to its factory settings then you can use the default password to access your router. Rebooting a router means cycling the power to it. If you want to reboot your router, take the following steps: Unplug the power connector from the back of the router and plug it back in. Wait about 30 seconds for the router to reboot. Your internet connection will drop when your router is rebooted. If someone is using a computer on your network to access the internet, you may want to warn them. When you reset your router, the following settings are changed: Router username and password. Wi-Fi username and password. ISP username and password. Port-forwards you set up. Any firewall settings you have made. Basically, any configuration changes that you have made to your router.
As you can probably tell from the list above, resetting your router is a serious matter. One should always proceed with caution. To reset your router, find the tiny reset button usually located at the back of the router. While the router is on, use a pin or the end of a paper clip to press and hold the reset button. You will need to hold it for about 10 seconds. Usually, you will want to wait for the lights to turn on the router. Depending on the make and model of your router the lights may start out blinking and change to solid, or they may start out solid and change to blinking. When you let go of the reset button, the router should be reset to the factory settings. Once the router is back up you should be able to login to it. Your router will have the same internal IP address after the reboot.
“6 Annoying Router Problems – And How to Fix Them. David Strom. Computer World. www.PCWorld.com. Web. 17 Jun 2010. 21 April 2017.