Smartphones in Network show "no Internet" periodically

Hi,

I have Pi-hole with unbound running in a Docker container. A few times per day all smartphones in the network show "no Internet" for a few seconds to minutes and resume working as intended after that. The Desktop didn't experience any errors.

Expected Behaviour:

Phones stay connected.

Actual Behaviour:

periodically all phones (only android, iOS not tested) show "no internet" and switch to mobile data for a few minutes

Tested:

Changing the DNS server in Pihole from unbound to 8.8.8.8

  • same result

Changing the DNS server in the DHCP settings of the router to 8.8.8.8

  • issue is gone

Further information:

Querry log of Pi-hole doesn't show any related blocked querrys
Diagnostics is empty

docker-compose:

version: '3.8'
services:
  pihole:
    container_name: pihole
    image: pihole/pihole:latest
    ports:
      - "53:53/tcp"
      - "53:53/udp"
      - "80:80/tcp"
    environment:
      TZ: "Europe/Berlin"  # Replace with your timezone
      FTLCONF_webserver_api_password: "1"
      DNSMASQ_LISTENING: "all"
      PIHOLE_DNS_1: "unbound#53"  # Point to unbound container
    volumes:
      - ./pihole:/etc/pihole
      - ./dnsmasq:/etc/dnsmasq.d
    restart: unless-stopped
    networks:
      dns_network: 
    cap_add:
      - NET_ADMIN
      - NET_RAW
      - CAP_SYS_NICE
      - CAP_SYS_TIME
    security_opt:
      - seccomp:unconfined
    depends_on:
      - unbound
  unbound:
    container_name: unbound
    image: klutchell/unbound:latest
    volumes:
      - ./unbound:/etc/unbound/custom.conf.d
    restart: unless-stopped
    networks:
      dns_network:
networks:
  dns_network:
    driver: bridge

Pihole Debug:
https://tricorder.pi-hole.net/rFp0lKSz/

Can be two things :

  • WiFi signal is poor.
  • The "Ping/Call Home" Android/Google domain is blocked or rate limited in your Pi-Hole.

In general :

The worse a WiFi signal gets the more the devices start to call home so there might be short "bursts" of "DNS SPAM" towards your Pi-Hole that goes over the 150 Queries per Second limit.

Disclaimer : IIRC what happend once on my own network or a friends network!

  • The WiFi signal is very good to good, as the router is just a few meters away.

  • Every time I noticed a disconnect I checked the querry log, but couldn't find anything related to blocked "Call Home" querry.

I tested 2 different routers

Unrelated to your network issue, I noticed 2 invalid environment variables:

  • DNSMASQ_LISTENING was used by Pi-hole v5.
    It was replaced by FTLCONF_dns_listeningMode.

  • There was never a docker environment variable called PIHOLE_DNS_1.
    There was a PIHOLE_DNS_ variable, but it was replaced by FTLCONF_dns_upstreams.

Please check the documentation for the new variables:
Docker - Upgrading from v5.x - Pi-hole documentation

Oh, Thanks.
That explains why I had to set those in the WebUI.

Similar thing here. "no data connection" when using pihole. Toggling Private DNS to dns.adguard.com for example restores the connection.