The issue I am facing:
Pi-hole is defeated when connected to the local TP-Link Deco X20 mesh network.
Details about my system: Hardware
Modem: Motorola MG7700
Hardware: RaspberryPi Zero-W
Mesh System: TP-Link Deco X20
Software
Raspbian Lite OS
Pi-hole installed on the RaspberryPi Zero-W
What I have changed since installing Pi-hole:
I recently set up a TP-Link Deco X20 to increase the Wi-Fi coverage around my house. Pi-hole continues to correctly block domains from the UI Adlist when I am using either the 2.4 or 5GHz connection from my modem but when I connect to the network via the Deco X20 connection those domains are accessible (Pi-hole is defeated).
Things I have tried:
I have updated Pi-hole and rebooted my modem.
Today I changed the Deco X20 mode from "Wi-Fi Router (Default)" to "Access Point".
Additional thoughts:
I thought about forcing my DHCP leases to renew but I have not been able to find good information on how to do this.
Also both my modem and Pi-hole have DHCP enabled because if I disable it in my modem then my network stops working.
Please let me know if I need to provide any more information (screenshots, logs etc). Any help is appreciated!
I'm also still experiencing some trouble getting Deco X20 to play together with my pihole, but at least it's functional now. Several things to keep in mind:
If you put the Deco in router mode, it will create its own subnet in which itself is both DHCP and DNS server - there does not seem to be any way to disable this. So even if you connect all your devices (including pihole) in the same subnet via Deco, there is no way to have your other devices automatically use that pihole DNS server.
If you put the Deco in access point mode but with the SmartDHCP option enabled, it still tends to run its own conflicting DHCP server.
The only way I found things to run reliably is put the Deco in access point mode and disable SmartDHCP. Also if you use a wired connection between the Deco's, it's recommended to connect the secondary Deco nodes via the main Deco (eg. don't connect them all directly to your router).
My remaining issue is that I cannot seem to control the IP address that pihole assigns to the Deco(s). I can see its MAC address in the static leases list (and it matches the incoming DHCPDISCOVER request), but still pihole assigns a random different IP address from the 'free-for-all' range. How could I diagnose this DHCP behavior?
Small addendum to the last bullet in previous post: it turns out I had configured a static IP lease outside the subnet (191.168...) , which makes pihole silently ignore the entry. Took me 3 days to figure that out...