I have a small Fritzbox 7312 and I installed OpenWRT onto it. I would like to use this Fritzbox 7312 as wifi repeater, by means of bridging the LAN port to the WLAN port (yes, LAN->WLAN). My main router provinding internet is a Fritzbox 7330 with stock firmware, onto which I cannot install openWRT, because I'm using the DECT functionality for telephones. As far as I read, openwrt has no support for it.
This Fritzbox 7330 router isn't able to cover all the house with the wifi signal and some devices cannot connect to internet at all. So, what I'm trying to do is to wire both routers to the LAN ports (LAN2 on 7330 and LAN1 on 7312) and create a bridge from the LAN port to the WLAN interface on the Fritzbox 7312. I would like the devices on the repeater side to be on the same subnet as the main router. I have read several tutorials (e.g: https://openwrt.org/docs/guide-user/network/wifi/dumbap https://openwrt.org/docs/guide-user/network/wifi/bridgedap relay_configuration etc), but I guess all of them are bridging the interfaces the other way around (WLAN->LAN).
So my question is: How can I create this bridge?