DNS resolve timeout outside of localhost

[Rechigo]

Whenever I try to make a DNS query on any device on my network that isn't the pihole server (localhost), the request ends up timing out. I'm not sure what the issue is here.

What I've tried:

• Pinging pi-hole ip to confirm it works
• Toggled "Listen on all interfaces, permit all origins" in settings
• nmap scan to confirm port 53 is open both TCP & UDP * Disabling ufw temporarily to confirm it's not a firewall issue
• Performed queries via multiple different computers via nslookup nslookup <domain> <pi-hole server IP>, all timed out
• Reconfiguring pi-hole pihole -r

What works so far:

• Local DNS queries from the pi-hole server resolve fine

Debug Token:

https://tricorder.pi-hole.net/FVoINvA5/

[jfb]

Something is interfering with port 53 traffic on your network:

*** [ DIAGNOSING ]: Name resolution (IPv4) using a random blocked domain and a known ad-serving domain
[✓] gjapplog.ucweb.com is 0.0.0.0 on lo (127.0.0.1)
[✗] Failed to resolve gjapplog.ucweb.com on enp1s0f0 (192.168.1.235)
[✓] gjapplog.ucweb.com is 0.0.0.0 on tun0 (10.8.0.1)
[✗] Failed to resolve gjapplog.ucweb.com on docker0 (172.17.0.1)
[✓] doubleclick.com is 142.250.72.142 via a remote, public DNS server (8.8.8.8)

*** [ DIAGNOSING ]: Setup variables
    PIHOLE_INTERFACE=enp1s0f0
    IPV4_ADDRESS=192.168.1.235/24

Additionally, your DHCP server is passing out a DNS other than Pi-hole, along with the Pi-hole IP. This will lead to some of your DNS traffic bypassing Pi-hole.

     DHCP options:
      Message type: DHCPOFFER (2)
      server-identifier: 192.168.1.1
      lease-time: 43200 ( 12h )
      renewal-time: 21600 ( 6h )
      rebinding-time: 37800 ( 10h 30m )
      netmask: 255.255.255.0
      broadcast: 192.168.1.255
      domain-name: "lan"
      dns-server: 192.168.1.235
      dns-server: 1.1.1.1
      router: 192.168.1.1
      --- end of options ---

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…

[Rechigo]

There is a Cloudflare DNS being given by the router because I assumed (incorrectly) that it would only be used as a secondary/fallback DNS server in the event that my pi-hole server went down.

As for what's interfering with traffic on port 53, I don't know, but I know it is something on my server. I tried running the same nslookup <domain> <pi-hole server ip> again on my computer, except this time I ran a tcpdump -Q in port 53 on my pi-hole server to see whether or not my request was making it to the server, which it is:

What things should I look for as possible causes now that I have verified that the requests are making it to my server?