Almost all requests coming from the router despite DHCP server being enabled

[yobson]

Expected Behaviour:

Requests should be coming from the individual devices

Actual Behaviour:

Almost all of them go through the router first

Debug Token:

https://tricorder.pi-hole.net/YYMuNTjs/

I have disabled the default DHCP server on my router and enabled the one in pi hole but almost all DNS requests still go through the router first, they still end up going through the pi hole since I have set the DNS server of the router as the pi hole but this means I can't see which requests are coming from which devices and cannot set specific devices to specific groups. Even when I go into a device's settings and specifically set the DNS server as the pi hole's IP address still the majority of the requests come from the router and not the device itself.

[jfb]

Have you renewed the DHCP leases on all clients?

[yobson]

I have the lease time set to infinite, I tried removing all the existing leases and restarting the pi but this didn't help. I find it strange that some requests do come from the individual devices and others don't, even from the same device.
Example:

All of these requests are coming from my desktop but most are going through the router first and not straight to the pi.
I even have manually set the DNS server of this device to the pi

[deHakkelaar]

@yobson

Above screenshot appears to be from a Windows client.
If you set both to "Obtain ... automatically", what do below ones show run on that client on a CMD prompt:

netsh interface ipv4 show dnsservers

netsh interface ipv6 show dnsservers

[yobson]

Configuration for interface "Ethernet"
    DNS servers configured through DHCP:  192.168.1.200
    Register with which suffix:           Primary only

Configuration for interface "Ethernet"
    DNS servers configured through DHCP:  fe80::d635:1dff:fe05:be6c%12
                                          fe80::d635:1dff:fe05:be6c%12
    Register with which suffix:           Primary only

[deHakkelaar]

@yobson

Configuration for interface "Ethernet"
    DNS servers configured through DHCP:  fe80::d635:1dff:fe05:be6c%12
                                          fe80::d635:1dff:fe05:be6c%12

Who/what are above fe80:: IP's?

Pi-hole needs to be the only DNS server for your clients:

Why should Pi-hole be my only DNS server?

Reduced Ad Blocking Capability The main reason you should Pi-hole as your only DNS server is that you will see increased performance in the blocking of ads. If you have two DNS servers (Pi-hole and something else), your network clients may not always query Pi-hole for name resolution. If a query happens to be answered from a non-Pi-hole DNS server, your block lists will not apply (since that DNS server doesn't know about them). All Queries Need To Go Through Pi-hole First Since other DNS se…

[Bucking_Horn]

@yobson

fe80::d635:1dff:fe05:be6c%12

It looks like your Technicolor router advertises its own IPv6 address as DNS server.
Hence, any IPv6 capable client may by-pass Pi-hole via IPv6.

To avoid IPv6 by-passes, you've got to configure your router to stop advertising its own IPv6 address and advertise Pi-hole's IPv6 address instead.

If your router doesn't offer such a configuration option, consider disabling IPv6 altogether.
If your router doesn't support that either, clients will by-pass Pi-hole via IPv6.

You have to consult your router's documentation and support for further details on its IPv6 configuration options.

[yobson]

Disabling IPv6 on the router worked, thanks!