I was going to post my own thread, but I feel like this is the exact same thing I am experiencing as well. The pihole had been working perfectly fine with no issues for quite some time, but about 3-4 weeks ago I started seeing this same behavior and haven't been able to figure out what exactly is going on. I probably need to document things a little better, but I feel like it may be better after rebooting the pihole for a short period of time. If I remove the pihole I don't notice any slowness issues.
I have a google wifi mesh setup. The pihole is configured for DHCP and DNS, and I also have pivpn setup on the rapsberry pi with the pihole. Not really sure what else to do at this point but take the pihole offline because it makes the internet so frustrating to use when it takes > 10 seconds to load a webpage.
I think you have a different issue, so I moved your post.
From your debug log: there are two DHCP servers on your network, one is your PI-hole , one is your router. Both advertise themselves as DNS servers. Additionally, your Pi is not able to send DNS packets to a public upstream DNS server.
✓] IPv4 address(es) bound to the eth0 interface:
192.168.86.2/24 matches the IP found in /etc/pihole/setupVars.conf
*** [ DIAGNOSING ]: Name resolution (IPv4) using a random blocked domain and a known ad-serving domain
[✓] serwis-laptopow24.pl is 0.0.0.0 via localhost (127.0.0.1)
[✓] serwis-laptopow24.pl is 0.0.0.0 via Pi-hole (192.168.86.2)
[✗] Failed to resolve doubleclick.com via a remote, public DNS server (8.8.8.8)
*** [ DIAGNOSING ]: Discovering active DHCP servers (takes 10 seconds)
Scanning all your interfaces for DHCP servers
Timeout: 10 seconds
WARN: Could not sendto() in send_dhcp_discover() (/root/project/src/dhcp-discover.c:223): Network is unreachable
* Received 300 bytes from eth0:192.168.86.1
Offered IP address: 192.168.86.2
Server IP address: 192.168.86.1
Relay-agent IP address: N/A
BOOTP server: (empty)
BOOTP file: (empty)
DHCP options:
Message type: DHCPOFFER (2)
server-identifier: 192.168.86.1
lease-time: 86400 ( 1d )
renewal-time: 43200 ( 12h )
rebinding-time: 75600 ( 21h )
netmask: 255.255.255.0
broadcast: 192.168.86.255
router: 192.168.86.1
domain-name: "lan"
dns-server: 192.168.86.1
--- end of options ---
* Received 300 bytes from eth0:192.168.86.2
Offered IP address: 192.168.86.6
Server IP address: 192.168.86.2
Relay-agent IP address: N/A
BOOTP server: (empty)
BOOTP file: (empty)
DHCP options:
Message type: DHCPOFFER (2)
server-identifier: 192.168.86.2
lease-time: 86400 ( 1d )
renewal-time: 43200 ( 12h )
rebinding-time: 75600 ( 21h )
netmask: 255.255.255.0
broadcast: 192.168.86.255
dns-server: 192.168.86.2
domain-name: "lan"
router: 192.168.86.1
--- end of options ---
DHCP_ACTIVE=true
DHCP_START=192.168.86.3
DHCP_END=192.168.86.251
DHCP_ROUTER=192.168.86.1
Yes, due to the inability to fully disable DHCP on a google wifi routers, I limited the DHCP of the google wifi to the .2 address which is statically assigned to the pihole. This had not seemed to be an issue, as everything seemed to have been working fine for quite some time before I began experiencing the slow page loading issue.
What do you mean by "pi is not able to send DNS packeets to a public upstream DNS server"? If that was the case, I wouldn't be able to resolve domains at all correct?
I didn't make any specific changes, I'm not sure exactly when I started seeing the issue, but I think there was an update to the pihole software somewhere around the time I feel I started seeing the problem.
I do not currently have a firewall configured on the raspberry pi hosting the pihole installation.
Did you run the commands from a client or the Pi device itself? Because it forwarded the request to Server: 127.0.0.53 which is the localhost. Instead, it should have used 192.168.86.2 as DNS server. Do you run any software on this client that might interfere with DNS? AVAST Real Site?
Do you experience the slowness on all of your clients?
Hmm. No, I did not run these from the pihole itself. I ran these from my laptop running pop-os. Unless something is baked in to a stock installation of pop-os on a System76 laptop, there shouldn't be anything messing with DNS resolution. So that does seem odd now that you mention it. I'll search around and see if I can understand why that is happening better. (Edit: Ok, it looks like that 127.0.0.53 is normal for a system using systemd-resovle service, so I don't think that is an issue.)
systemd-resolve --status shows:
Global
LLMNR setting: no
MulticastDNS setting: no
DNSOverTLS setting: no
DNSSEC setting: no
DNSSEC supported: no
Link 2 (enp36s0)
Current Scopes: none
DefaultRoute setting: no
LLMNR setting: yes
MulticastDNS setting: no
DNSOverTLS setting: no
DNSSEC setting: no
DNSSEC supported: no
Link 3 (wlp0s20f3)
Current Scopes: DNS
DefaultRoute setting: yes
LLMNR setting: yes
MulticastDNS setting: no
DNSOverTLS setting: no
DNSSEC setting: no
DNSSEC supported: no
Current DNS Server: 192.168.86.2
DNS Servers: 192.168.86.2
2600:6c5e:2e7f:5a2e:40df:5bff:fe7d:19b0
2600:6c5e:2e7f:5a2e:f7ee:3e0a:a716:fe9a
DNS Domain: ~.
And yes, it seems the slowness is seen on all devices.
So. I'm not sure if it's fixed fixed now or not, because there are times where it seems to be better than others. But this morning I was monkeying around a bit. Now, this problem definitely started prior to me enabling IPV6 on my network, I had IPV6 disabled on my router when I originally setup the pihole, and only recently enabled it after reading through some posts where others were discussing slow loading webpages. I realized this morning that I did not have everything configured quite right for utilizing IPV6 on the pihole. I believe I have that all correct now. And things seem to be pretty normal at the moment. I guess time will tell here if it's simply fixed, or if this is just temporary.
Ok, while sorting out the ipv6 stuff seemed to help some, it still didn't feel quite as right as it should. I just took my pihole completely offline and set the router back up for dhcp and dns, and everything loads up so much faster. It's quite noticeable. I'm not sure if maybe it could be something with the hardware or what, but for now I guess I will leave it offline for the time being. Maybe I'll try running it from a docker image on my server and see if I have better results with that.