Test to see is there are DNS issues

chris · 28 November 2025 10:40

See this thread:

github.com/moby/moby

29.1.0 breaks the embedded DNS resolver

opened 01:49AM - 28 Nov 25 UTC

closed 10:31AM - 28 Nov 25 UTC

afonsofrancof

kind/bug area/networking status/confirmed area/networking/dns version/29.1

### Description Updating from 29.0.4 to 29.1.0 breaks all DNS connectivity betw…een containers and the embedded DNS resolver. 127.0.0.11#53 rejects connectivity on port 53. Every process outputs this (management being my container name in this example) ``` tcp: lookup management on 127.0.0.11:53: server misbehaving ``` When trying to nslookup from inside a container I get this ``` nslookup management 127.0.0.11 Server: 127.0.0.11 Address: 127.0.0.11:53 ** server can't find management: SERVFAIL ** server can't find management: SERVFAIL ``` ### Reproduce 1. Upgrade to 29.0.1 2. That's it. ### Expected behavior DNS should work ### docker version ```bash Client: Docker Engine - Community Version: 29.1.0 API version: 1.52 Go version: go1.25.4 Git commit: 360952c Built: Thu Nov 27 16:42:45 2025 OS/Arch: linux/amd64 Context: default Server: Docker Engine - Community Engine: Version: 29.1.0 API version: 1.52 (minimum version 1.44) Go version: go1.25.4 Git commit: 710302e Built: Thu Nov 27 16:42:45 2025 OS/Arch: linux/amd64 Experimental: false containerd: Version: v2.1.5 GitCommit: fcd43222d6b07379a4be9786bda52438f0dd16a1 runc: Version: 1.3.3 GitCommit: v1.3.3-0-gd842d771 docker-init: Version: 0.19.0 GitCommit: de40ad0 ``` ### docker info ```bash Client: Docker Engine - Community Version: 29.1.0 Context: default Debug Mode: false Plugins: buildx: Docker Buildx (Docker Inc.) Version: v0.30.1 Path: /usr/libexec/docker/cli-plugins/docker-buildx compose: Docker Compose (Docker Inc.) Version: v2.40.3 Path: /usr/libexec/docker/cli-plugins/docker-compose Server: Containers: 48 Running: 45 Paused: 0 Stopped: 3 Images: 57 Server Version: 29.1.0 Storage Driver: btrfs Btrfs: Logging Driver: json-file Cgroup Driver: systemd Cgroup Version: 2 Plugins: Volume: local Network: bridge host ipvlan macvlan null overlay Log: awslogs fluentd gcplogs gelf journald json-file local splunk syslog CDI spec directories: /etc/cdi /var/run/cdi Swarm: inactive Runtimes: io.containerd.runc.v2 runc Default Runtime: runc Init Binary: docker-init containerd version: fcd43222d6b07379a4be9786bda52438f0dd16a1 runc version: v1.3.3-0-gd842d771 init version: de40ad0 Security Options: seccomp Profile: builtin cgroupns Kernel Version: 6.12.57+deb13-amd64 Operating System: Debian GNU/Linux 13 (trixie) OSType: linux Architecture: x86_64 CPUs: 16 Total Memory: 28.3GiB Name: togepi ID: 41fd9997-a498-44ae-90ee-35b16015c244 Docker Root Dir: /var/lib/docker Debug Mode: false Experimental: false Insecure Registries: ::1/128 127.0.0.0/8 Live Restore Enabled: false Firewall Backend: iptables ``` ### Additional Info _No response_

The one box above seems to be working so perhaps it is all OK!

chris · 4 December 2025 12:30

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