Pihole stopped working

[mushweed]

Hey,

my pihole was running fine but suddenly stopped working yesterday. It just received no more requests, despite me changeing anything.

Today I set it up completely from scratch, but I can't get it to work anymore

Expected Behaviour:

pihole as it should

Actual Behaviour:

pihole not receiving any queries

Debug Token:

https://tricorder.pi-hole.net/s9wi1118zk

[jfb]

Your debug log shows that Pi-hole is working. It does not appear to be receiving any queries from the network.

One thing I note is that your only adlist is not in the correct format for Pi-hole, and should not be used. This is what happens when you try to import this list into Pi-hole (output from pihole -g):

  [i] Target: https://easylist.to/easylist/easylist.txt
  [✓] Status: Retrieval successful
  [i] Received 26581 domains, 20175 domains invalid!
      Sample of invalid domains:
      - 2.0]
      - (easylist@protonmail.com).
      - &ad.vid=$~xmlhttprequest
      - &advertiserid=$domain=~bee.gl|~cpashka.ru
      - -ad.jpg?

Get rid of this list and use either one or both of the defaults, or any of the lists at firebog.net

Restoring default Pi-hole adlist(s)

Pi-hole ships with optional adlist(s) (publicly maintained block lists), which you can enable if you choose. If you find that you need to restore the default list(s), they are as follows - current as of the V5.2 release and a pending change to remove a discontinued list. https://raw.githubusercontent.com/StevenBlack/hosts/master/hosts To restore these lists to your Pi-hole, you have several options: Pi-hole V4: From the web Admin GUI > Settings > Blocklists you can paste any of the URL's …

As to why your Pi-hole isn't receiving DNS queries, let's take a look at what DNS a client is using:

From a client that you believe should be connected to the Pi-Hole for DNS, from the command prompt or terminal on that client (and not via ssh or Putty to the Pi), what is the output of

nslookup pi.hole

nslookup pi.hole 192.168.50.155

[mushweed]

Hi,

thanks for the input. This is the reply:

C:\Users\XX>nslookup pi.hole
Server: UnKnown
Address: 2a02:810d:41bf:fd0f::1

*** pi.hole wurde von UnKnown nicht gefunden: Non-existent domain.

C:\Users\XX>nslookup pi.hole 192.168.50.155
Server: raspberrypi
Address: 192.168.50.155

Name: pi.hole
Addresses: 2a02:810d:41bf:fd0f:29f3:c128:682:1fe0
192.168.50.155

[Bucking_Horn]

Did you find out where that 1.1.1.1 DNS server came from? How did you get rid of it?

Your clients (at least your Windows one) are still not using Pi-hole as DNS. Judging by its IPv6 prefix, that's rather another device from your local network most likely your router.

Your router may offer itself or your ISP's servers via IPv6, and also some router models (like ASUS RT-AC68) are known to distribute themselves in addition to any custom DNS servers, no matter what you configure.

[mushweed]

I tired to assign manual IPs and force them to choose a certrain DNS, but no luck so far.

For my windows i needed to enter the DNS in the windows setting. Never had to do that before. I don't get why it changed.. Was working well for month..

All my devices take the router IP and 1.1.1.1 als DNS, even i entered pihole as DNS in the router settings...

I am totally confused.. factory resett my router, didn't change anything...

[Bucking_Horn]

If you didn't change anything DNS related yourself, a recent firmware update for your router may have introduced those changes.
Also, some routers do offer features dubbed parental control, intelligent protection, OpenNAT or similar that may interfere with DNS.

[deHakkelaar]

Those screenshots are from an Asus router.
Bucking_Horn is correct:

@Bucking_Horn

Your router may offer itself or your ISP's servers via IPv6, and also some router models (like ASUS RT-AC68 ) are known to distribute themselves in addition to any custom DNS servers, no matter what you configure.

Most likely the router is also pushing its own IP address for DNS to the clients alongside the DHCP-->DNS setting from the screenshot.
If want to know for sure, install nmap on the Pi-hole host:

sudo apt install nmap

And do a DHCP discovery with below replacing <ROUTER_IP_ADDRESS> with the actual IP:

sudo nmap -sU -p67 --script dhcp-discover <ROUTER_IP_ADDRESS>

If output for above one shows multiple DNS servers on the "Domain Name Server" line and one of them isnt Pi-hole, you cant use the Asus router with stock firmware to hand out IP details via DHCP.
I know of below two alternatives options:

Configuring the WAN DNS settings on router in light of pihole, AND UNbound running on pihole

Looks like an Asus router. Best options are: Default router WAN settings; Enable the DHCP service in Pi-hole; Disable the DHCP service on the router; Reboot a client to renew DHCP lease and test with nslookup pi.hole in a cmd prompt. Flash the Asus stock firmware with the Merlin one (if the router is on the supported list) and push Pi-hole's IP address through DHCP to the clients as the only DNS server; Make sure the "Advertise router’s IP in addition to user-specified DNS" setting on…

[Coro]

@mushweed

Never had to do that before. I don't get why it changed.. Was working well for month..

How about Windows Update? They know what is good for you and sometimes install updates automatically, when they say the update is important. Something changing the networking behavior could very well be such a thing.

[mushweed]

I changed DHCP now to pihole and it seems to be working quite good.

But there is no setting to have certain devices using different DNS? My TV is spamming the pihole with pings etc.

[jfb]

Secondary DNS Server for DHCP

I have it running in different environments (two of them at an enterprise level, one with more than 100 clients). They all run on Raspberry Pi hardware in various revisions. They never failed so far, so I wouldn't bother too much. A clever idea might be to set up two independent Pi-hole's and (two distinct devices in the same network) and set up those two IPs as "primary" and "secondary" servers. All devices should be able to resolve domains, even if one of them fails for some reason. The cost…