Path to the problem
In the new apartment where I live in, a single router (vodafone) takes the internet signal and shares it over hubs to four other routers (3 tp link, 1 fritzbox) and one access point (tp link).
In the past we had many issues regarding not being able to access certain websites sometimes (felt very random). I contacted my provider and they told me that they see no issue on their side, but that maybe DHCP caused problems. That sounded reasonable. I checked the routers and indeed they all had DHCP activated. Therefore I decided to setup everything anew.
What I have done
Preparation
I unplugged all routers from the hubs (and therefore the router taking the internet initially) and reset them.
Connecting the other routers and access points
Vodafone ("directly" connected with the internet)
The vodafone router 192.168.0.1
has internet and works as expected.
Fritzbox
I then configured the fritzbox router and set his gateway to the vodafone's router ip 192.168.0.1
and deactivated the DHCP server. I also gave it a free static ip of 192.168.0.2
I made sure the subnet was 255.255.255.0
on both machines. The router restarted and now I am unable to connect to its wifi. I connected the router via the same Hub strategy like before with the vodafone router. A lamp changed on the router. I still can't connect to it via wifi. I also can't connect to it from the vodafone router and I do not see it connected to the vodafone router in the vodafone panel (maybe it is listed as unknown).
TP Link Router
Same story as Fritzbox Router. However, I noticed that before this router was connected to the Vodafone Router via the internet socket, but I don't think that is relevant
TP Link AP
This one just worked directly. I deactivated DHCP though and gave it a static ip.
What I am looking for
I currently don't know why the vodafone router is not talking to the other routers. I can imagine that I can't connect via wifi, because those routers aren't giving me an IP anymore as dhcp is disabled on them. However, vodafone should do this for them; shouldn't it? I don't know how to debug this issue any further as most tutorials online just mention activating DHCP, using a static IP and setting the gateway, but do not cover the issues I experience.