While changing the MTU level of your Linksys Router a user has to set the current Internet speed in the provided field. You can take the help of the Speed test option in the Linksys Smart Wi-fi interface to check the current upload and download speed of your Wi-fi connection. A user must type the Internet speed in the required field. You can measure the Internet speed either manually or automatically through the Speed test feature of the linksyssmartwifi.com window.