Pi-Hole stops blocking ads

[Samsa]

Expected Behaviour:

Ads should always be blocked

Actual Behaviour:

Ads getting blocked but not always. If i reconnect the devices (Wifi and wired ones) it will work for some time but then stops working again.

Debug Token:

8pd9g0ewet

[jfb]

This is frequently due to another DNS path available to the clients. If given two paths to the internet, they typically with find both. When you re-connect them, they typically use the first DNS they see, which in your case is Pi-Hole. As time goes by, they can find the other DNS path.

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…

[Samsa]

Pi-hole is the only DNS i'm using. As far as i know there is also no fallback DNS on the router (Fritzbox) nor repeater. If i take a look at the current network-settings on the devices (Smartphone) the DNS is always the Pi Hole IP.
Till one weak ago, it all worked without problems.

[jfb]

What is the output of this command from the Pi terminal:

echo ">stats" | nc localhost 4711

[Samsa]

$ echo ">stats" | nc localhost 4711
domains_being_blocked 135971
dns_queries_today 12381
ads_blocked_today 2641
ads_percentage_today 21.331072
unique_domains 919
queries_forwarded 6952
queries_cached 2788
clients_ever_seen 16
unique_clients 16
dns_queries_all_types 12452
reply_NODATA 119
reply_NXDOMAIN 15
reply_CNAME 395
reply_IP 1090
status enabled
---EOM---

[jfb]

This data indicates that the Pi-Hole is actively blocking domains.

We'll take a look at your debug log.

[Samsa]

Thanks for your help!

[Jeroen1]

Disabled ipv6 on the fritzbox?

[Samsa]

Yes. - 10 characters

[Jeroen1]

Also the ipv6 part in the fritz internet settings I assume?
Only 1 dhcp server in the lan I assume?

What does ipconfig /all say on a device with ads?

[Samsa]

There only one option to activate IPv6 (and it's only for internet settings) and it's disabled.
The Fritzbox one is the only DHCP but most of the clients have a static IP.

I'm on Ubunto so i can give you the output of nmcli dev show enp3s0
When it's working it looks like this:

nmcli dev show enp3s0
GENERAL.GERÄT:                          enp3s0
GENERAL.TYP:                            ethernet
GENERAL.HWADDR:                         7C:8B:CA:02:5F:E5
GENERAL.MTU:                            1500
GENERAL.STATUS:                         100 (verbunden)
GENERAL.VERBINDUNG:                     Kabelnetzwerkverbindung 1
GENERAL.CON-PFAD:                       /org/freedesktop/NetworkManager/ActiveConnection/0
WIRED-PROPERTIES.TRÄGERFREQUENZ:        an
IP4.ADRESSE[1]:                         192.168.178.22/24
IP4.GATEWAY:                            192.168.178.1
IP4.ROUTE[1]:                           dst = 169.254.0.0/16, nh = 0.0.0.0, mt = 1000
IP4.DNS[1]:                             192.168.178.26
IP4.DOMÄNE[1]:                          fritz.box
IP6.ADRESSE[1]:                         fd00::1:4dbf:3472:2fda:e86c/64
IP6.ADRESSE[2]:                         fd00::1:e255:fcb1:978f:3643/64
IP6.ADRESSE[3]:                         fe80::f5a:eea5:9f9:a885/64
IP6.GATEWAY:                            fe80::56fa:3eff:fe82:76da
IP6.DNS[1]:                             fd00::1:56fa:3eff:fe82:76da
IP6.DNS[2]:                             fe80::56fa:3eff:fe82:76da

If it's not working it looks like this:

nmcli dev show enp3s0
GENERAL.GERÄT:                          enp3s0
GENERAL.TYP:                            ethernet
GENERAL.HWADDR:                         7C:8B:CA:02:5F:E5
GENERAL.MTU:                            1500
GENERAL.STATUS:                         100 (verbunden)
GENERAL.VERBINDUNG:                     Kabelnetzwerkverbindung 1
GENERAL.CON-PFAD:                       /org/freedesktop/NetworkManager/ActiveConnection/1
WIRED-PROPERTIES.TRÄGERFREQUENZ:        an
IP4.ADRESSE[1]:                         192.168.178.22/24
IP4.GATEWAY:                            192.168.178.1
IP4.DNS[1]:                             192.168.178.26
IP4.DOMÄNE[1]:                          fritz.box
IP6.ADRESSE[1]:                         fd00::1:4dbf:3472:2fda:e86c/64
IP6.ADRESSE[2]:                         fd00::1:e255:fcb1:978f:3643/64
IP6.ADRESSE[3]:                         fe80::f5a:eea5:9f9:a885/64
IP6.GATEWAY:                            fe80::56fa:3eff:fe82:76da
IP6.DNS[1]:                             fd00::1:56fa:3eff:fe82:76da
IP6.DNS[2]:                             fe80::56fa:3eff:fe82:76da

The part IP4.ROUTE[1]: dst = 169.254.0.0/16, nh = 0.0.0.0, mt = 1000
is missing

//Edit: Ok, it's also missing when it's working. Don't know why it showed up the first time.

[Jeroen1]

@Samsa

IP6.DNS[1]: fd00::1:56fa:3eff:fe82:76da IP6.DNS[2]: fe80::56fa:3eff:fe82:76da

That is your fritzbox?....Something is sending ipv6 dns and gateway info to your clients.....
Or is this a manual entry?

[Samsa]

I think i have found the culprit! The TV-Receiver (Unitymedia Horizon Recorder) got an update a few days ago. Despite everything network related was disabled, it seems that the Receiver somehow startet its own DNS. (You are right, i missed the entry) I've pulled the networkcable and now it looks like that everything went back to normal. I'll report back after some time. Thanks guys!

[Jeroen1]

Hi,

Yes, do never physicly connect the ziggo horizon with your network.

[Samsa]

This piece of hardware is just pure cancer...