My problem is that I want to build a Wlan mesh over this 3 routers, but I don't know really how.
My newest approach is to try it with the 802.11s but if I connect my notebook with one of the TL-WDR4300, I can't communicate with the Fritzbox and vice versa.
I think my knowledge about OpenWrt is also a fundamental problem. I tried different tutorials but every single one with the same outcome (see above).
Currently you are just connecting all 3 routers over wifi?
Since I suspect the stock firmware of the fritzbox to not play well with the other two devices my question is what you can / can not ping? Do the 2 WDRs "see" each other?
I have done some meshing including a fritzbox with OpenWrt on it and used batman-adv. That would be a guaranteed working approach. But it takes some efford to understand and set up for the first time.
Yes, so layer 1 connection is working. Which is good. To clarify what I actually wanted to know: can you ping one TL-WDR4300 from the other when they are both in wifi mesh range to each other.
trying to figure out if OpenWrt devices or the fritzbox are the issue here.