@DarknessxKing Archer A6 doesn't support Bandwidth Limit feature. It has been replaced with QoS. Try configuring QoS and check if that works for you - details (Case 3).

@Adam039 You probably have to login with your local administrator password and then bind the TP-Link ID to the device to start using it - details. If the this is a new device its administrative...

@Altimox AX55 doesn't have a range extender mode in its operating mode menu. You could use it for building an easymesh network with other easymesh compatible router though - details.

@PickleRick333 For building easymesh with ethernet backhaul use this guide. For building easymesh with wirelsss backhaul use this guide. If you still can't build the easymesh use this troubleshooting...

@Didier_Jakarta Use this guide to configure 3G/4G backup feature.

@DavideD Ethernet ports on the modem router are bridged by default and those two devices should be able to communicate with each other.