@SnaffyNoo You can have mesh between these devices only if you connect them wirelessly. When RE815XE is in AP mode (wired) it won't support building a mesh network.

@hopekiran What about your range extender, is it TP-Link RE450 v4.8 ? It has to be with the latest FW release I presume RE450(US)_V4.8_1.0.20 Build 230213, which supports Easymesh too.

@800 With VR600 traffic can be prioritized with QoS only - here's a guide on that.

@hopekiran It depends which HW version is your RE450 device. Only RE450 V4 supports Easymesh - details. You can check the HW version on the device sticker - here. In general when the main router is...

@Asciavadas If you have troubles setting up the router via tether app you can use this video guide. In order to do that successfully you have to reset the device to its factory defaults - press and...

@HomeNotifier Port 22 is used by the tether app (details), while port 53 is for the local DNS requests to the router.