So my setup is like that: MODEM (aka router with PPPoE Passtrough) - ROUTER (handles EVERYTHING except wifi) - SWITCH (for all ethernets in my house) - DECO MAIN (ethernet) DECO 2(ethernet) -DECO 3...

@Tor-Arne okay do you have any tips for good settings in the fritzbox web site, should i change some things? What are the features on the fritzbox youre using? Very late reply but anyway

First off all, i dont know if its the router (its a very good one, fritzbox 7590) or the deco that crashes. Im downloading at my full speed and then it stops downloading and i cant enter the deco app...

@Tor-Arne in the AP-Mode i activated the Network of the fritzbox, normally i deactivate it bcz i dont need it. now the fritzbox does Wlan and the wlan of the fritzbox gets extended by my 3 decos...

@Tor-Arne in the AP Mode, the fritzbox works as Master and the other as Slaves right? so i use the fritzbox. in the Router Mode, the Fritzbox makes himself 1 network, and the decos make 1 network....

@Tor-Arne i updated my setup now. Now it is like this: Fritzbox(main router)--------Deco A(connected per Ethernet)-------Deco B(connected via WiFi with Deco A)--------Deco C (connected via Wifi with...