Slow DNS

Help
1

Hello everybody,

Im experiencing Problems with pihole in a raspberry pi Zero (First gen).

All the queries are very Slow. I have to change to mobile Internet to load Most of the websites.

I have a fritzbox 7412 to connect to Internet and a fritzbox 7530ax as an access point connected to a Switch Which connects to another Switch connected to the First fritz Box. In the fritz Box i set To Use pihole as Alternative dns Server. Somehow there are DNS queries Every second.

Maybe you can help. Here is my debug token:
https://tricorder.pi-hole.net/Iy6A3usW/

Regards.

2

First, you didn't configure Pi-hole as your sole DNS server:

This would allow your FB to by-pass Pi-hole completely via the other DNS server.
Pi-hole has to be the sole DNS server for your network.

In addition, configuring your FB that way (upstream Pi-hole) may close a partial DNS loop when Pi-hole's Conditional Forwarding would be enabled at the same time. Your debug log suggests that to be the case, which could well contribute to your observation of sometimes slow DNS resolution.
Note that CF won't be useful anyway if your FB is using Pi-hole as upstream, since that would make your FB the sole client of your Pi-hole.

Furthermore, your debug log shows your router's DHCP server is distributing its own IP as local DNS server:

*** [ DIAGNOSING ]: Discovering active DHCP servers (takes 10 seconds)
   Scanning all your interfaces for DHCP servers
   
   * Received 548 bytes from eth0:192.168.178.1
     Offered IP address: 192.168.178.35
     DHCP options:
      Message type: DHCPOFFER (2)
      router: 192.168.178.1
      dns-server: 192.168.178.1
    
   DHCP packets received on interface docker0: 0
   DHCP packets received on interface lo: 0
   DHCP packets received on interface eth0: 1

This would suggest that you've configured your FB to use Pi-hole as upstream DNS server.

While this would be a valid configuration, it would be preferred if you would configure your FB to distribute Pi-hole as local DNS server instead.

Have a look at Fritz!Box (EN) - Pi-hole documentation or - if you prefer German - at Fritz!Box (DE) - Pi-hole documentation for configuration examples.

3

Thanks for your reply. My fault, I configured the sole and alternative dns server in my fritz box to use pihole as upstream dns server.

I hope i understood you right. Either I have to deactivate CF or I have to set pihole as local dns server in my fritz box which is the preferred method right?

Regards.

4

Yes.

There are circumstances where you'd want to configure both and may accept the risk of a partial loop.

But if you are new to Pi-hole (which I assume you are), you may want to take it slowly - get a working configuration first, get familiar with Pi-hole and the way DNS works and impacts your network, and only adopt your configuration if you discover new requirements.

The links I've posted will help you getting on that path.

You may need some further configuration steps only if your FB router would have public IPv6 connectivity (according to your debug log, it doesn't).

5

Thank you very much for the explantations. I deactivated CF and set pihole in DHCP-Settings of the fritz box to use as local dns server. Now, I am also able to see every client in the query log instead of only the fritz box. So far everything is working pretty fast again.

6

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