I have a question: do I need to make my Raspberry Pi the new Wireless Access Point if I set the DHCP role via Pi-Hole (and of course disable it in my router)? Or can I keep using the router as AP and will the Pi-Hole give out IP addresses through the router to the network? It is a router provided by our ISP, meaning it's an all-in-one (modem, firewall, switch, router, access point, probably more). So, does DHCP pass through that (if I remember correctly, DHCP requests are never routed, but please correct me if I'm wrong)
Or does using Pi-Hole as DHCP server only work for the wired devices?
Keep the router as the access point, and disable DHCP on the router. All you are moving to the Pi-hole is the DHCP function.
Any device on your network can be a DHCP server if it has the capability. This is a broadcast service and not limited to a router.
Note that some ISP routers offer the users limited control options. If you can't disable DHCP on the router, you can restrict the router DHCP to a single IP (the IP of the Pi), and set up the DHCP in Pi-hole on a non overlapping range.
Unfortunately, I think I will need to keep some DHCP in the router. I forgot to mention that there's an ethernet cable between the router and the decoder for TV.
I will try completely disabling the DHCP in the router, and I'll hope everything keeps working. If not, I guess I'll set up a DHCP range of 1 IP address and reserve it to the MAC address of the decoder. If it still not works then, I guess I just have to set every device with a static, until I have enough money to buy a (decent) second router that I can plug in. It's a home setup, not a company or SOHO or something like that, so I don't like to make too much expenses for it.
This should work. It isn't relevant* whether the connection is via cable or wireless.
*) This comes with a very minor exception of some Google routers which seem to isolate these network from each other. Just that you've heard about it. We've seen it only once or twice while having helped thousands of users, so it seems rather unlikely to encounter this.
