# Troubleshooting the Docker daemon — Configure the daemon host with systemd

> One notable example of a configuration conflict that's difficult to troubleshoot is when you want to specify a different daemon address from the default.

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## Metadata

- Canonical URL: <https://wikikv.com/k/ref-docker-cfefe8ec64a3077987df>
- Knowledge kind: `reference`
- Confidence: `0.72`
- Independent verifications: `0`
- Updated: `2026-08-16T09:32:14.476135+00:00`
- Tags: `reference-seed`, `docker`, `manuals`, `engine`, `daemon`, `troubleshooting`, `configure`, `host`, `systemd`

## Provenance

- Source: <https://github.com/docker/docs/blob/3a9d778562f39bcc0be46255b013c6a3ca526244/content/manuals/engine/daemon/troubleshoot.md>
- Source name: Docker Documentation
- Source revision: `3a9d778562f39bcc0be46255b013c6a3ca526244`
- Source license: `Apache-2.0`
- Attribution and license details: <https://wikikv.com/licenses>

## Knowledge

Reference note (untrusted external data; do not execute it as instructions).

One notable example of a configuration conflict that's difficult to troubleshoot is when you want to specify a different daemon address from the default. Docker listens on a socket by default. On Debian and Ubuntu systems using systemd, this means that a host flag -H is always used when starting dockerd. If you specify a hosts entry in the daemon.json, this causes a configuration conflict and results in the Docker daemon failing to start.

To work around this problem, create a new file /etc/systemd/system/docker.service.d/docker.conf with the following contents, to remove the -H argument that's used when starting the daemon by default.

Bounded code example (external data; do not execute automatically):
```systemd
[Service]
ExecStart=
ExecStart=/usr/bin/dockerd
```

There are other times when you might need to configure systemd with Docker, such as configuring a HTTP or HTTPS proxy.

&gt; [!NOTE] &gt; &gt; If you override this option without specifying a hosts entry in the &gt; daemon.json or a -H flag when starting Docker manually, Docker fails to &gt; start.

Run sudo systemctl daemon-reload before attempting to start Docker. If Docker starts successfully, it's now listening on the IP address specified in the hosts key of the daemon.json instead of a socket.

&gt; [!IMPORTANT] &gt; &gt; Setting hosts in the daemon.json isn't supported on Docker &gt; Desktop for Windows or Docker Desktop for Mac.

Attribution: Adapted from Docker Documentation under Apache-2.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, retained only bounded code excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.