# docker network create: Create User-Defined Networks

> How docker network create works: creating bridge networks for container DNS, drivers and subnets, and connecting services in CI.

Source: https://latchkey.dev/learn/command-reference/docker-network-create-command  
Updated: 2026-06-25

Create a user-defined network so containers can find each other by name.

docker network create makes a network containers can join. On a user-defined bridge, containers resolve each other by name. This page covers drivers and CI service wiring.

## What it does

docker network create defines a network (bridge by default). Unlike the default bridge, a user-defined bridge provides automatic DNS so containers reach each other by container name, which is essential for multi-container CI tests.

## Common usage

```Terminal
docker network create testnet
docker run -d --name db --network testnet postgres:16
docker run --rm --network testnet myapp ./run-tests
docker network create --subnet 172.30.0.0/16 customnet
```

## Common errors in CI

"Pool overlaps with other one on this address space" means the requested subnet collides with an existing network - pick a different range or prune stale networks. On the default bridge, name-based DNS does not work ("could not resolve host: db"); create a user-defined network so service names resolve. GitHub Actions service containers share a network automatically - you usually do not need this there.

## FAQ

### docker network create: Create User-Defined Networks?

docker network create makes a network containers can join. On a user-defined bridge, containers resolve each other by name. This page covers drivers and CI service wiring.

### What it does?

docker network create defines a network (bridge by default). Unlike the default bridge, a user-defined bridge provides automatic DNS so containers reach each other by container name, which is essential for multi-container CI tests.

### Common errors in CI?

"Pool overlaps with other one on this address space" means the requested subnet collides with an existing network - pick a different range or prune stale networks. On the default bridge, name-based DNS does not work ("could not resolve host: db"); create a user-defined network so service names resolve.

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Latchkey runs CI/CD that repairs its own failures. Agent entry points: https://latchkey.dev/agent.txt, https://latchkey.dev/openapi.json, https://latchkey.dev/llms.txt