Pi-hole not responding to Macs

[stevedoc]

Please follow the below template, it will help us to help you!

Expected Behaviour:

Macs that are pointed to pi-hole should receive DNS responses from pi-hole.

Actual Behaviour:

I have 2 different Macs that both display the same issues reaching pi-hole for DNS resolution. They can ping the IP of the pi-hole, but they cannot get a response to DNS requests. dig @ apple.com will time out with "connection timed out: no servers could be reached".

However, other devices on the network seem to be working fine. The pi-hole dashboard shows increasing counters in all categories and tests from iPhones show pages being blocked by pi-hole. Issue seems to be limited to the Macs on the network.

Because the Macs cannot reach pi-hole they fail-over to the other DNS server configured in the router (1.1.1.1).

Debug Token:

PMuRnrxt

[jfb]

@stevedoc

Because the Macs cannot reach pi-hole they fail-over to the other DNS server configured in the router (1.1.1.1).

You should not have a DNS server available that is not a Pi-hole.

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…

@stevedoc

they cannot get a response to DNS requests.

One one of the Macs (and on the terminal on that Mac, not via ssh to Pi-hole), what is the output of the following commands:

nslookup pi.hole

nslookup pi.hole 192.168.22.53

scutil --dns

[stevedoc]

Thanks for the reply. I set up the secondary DNS (1.1.1.1) because without it, my hosts would not be able to browse anywhere when the pi-hole stop responding to them. When I see ads on one of the Macs, I would do a quick "dig" to see what DNS server I was using and then a dig directly to 192.168.22.53 to see if I could get a response from pi-hole. For whatever reason, pi-hole will randomly disappear from the Mac's perspective and they would switch over to 1.1.1.1. Doing the dig directly to the pi-hole would just time out.

Here is the output you requested. I manually set 192.168,22.53 as the only DNS server to gather this output. It should also be noted that other hosts on my network seem to be using the pi-hole without issue. I can try to verify that a bit more but I'm hoping to figure this out via the Macs if possible.

[~]$nslookup pi.hole
;; connection timed out; no servers could be reached

 [~]$
 [~]$nslookup pi.hole 192.168.22.53
;; connection timed out; no servers could be reached

[~]$
[~]$scutil --dns
DNS configuration

resolver #1
  nameserver[0] : 192.168.22.53
  flags    : Request A records
  reach    : 0x00020002 (Reachable,Directly Reachable Address)

resolver #2
  domain   : local
  options  : mdns
  timeout  : 5
  flags    : Request A records
  reach    : 0x00000000 (Not Reachable)
  order    : 300000

resolver #3
  domain   : 254.169.in-addr.arpa
  options  : mdns
  timeout  : 5
  flags    : Request A records
  reach    : 0x00000000 (Not Reachable)
  order    : 300200

resolver #4
  domain   : 8.e.f.ip6.arpa
  options  : mdns
  timeout  : 5
  flags    : Request A records
  reach    : 0x00000000 (Not Reachable)
  order    : 300400

resolver #5
  domain   : 9.e.f.ip6.arpa
  options  : mdns
  timeout  : 5
  flags    : Request A records
  reach    : 0x00000000 (Not Reachable)
  order    : 300600

resolver #6
  domain   : a.e.f.ip6.arpa
  options  : mdns
  timeout  : 5
  flags    : Request A records
  reach    : 0x00000000 (Not Reachable)
  order    : 300800

resolver #7
  domain   : b.e.f.ip6.arpa
  options  : mdns
  timeout  : 5
  flags    : Request A records
  reach    : 0x00000000 (Not Reachable)
  order    : 301000

DNS configuration (for scoped queries)

resolver #1
  nameserver[0] : 192.168.22.53
  if_index : 5 (en0)
  flags    : Scoped, Request A records
  reach    : 0x00020002 (Reachable,Directly Reachable Address)

[stevedoc]

I figured out the issue. The pihole was was using both wired (eth0) and wireless (wan0) and they both had the same IP address. I'm guessing this was causing some routing/switching confusion in the network that resulted in the periodic loss of connectivity to the pihole from the hosts. I've disabled the wireless interface and it's been stable. Thanks for the help.