docker network create: Create User-Defined Networks

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.

Related guides

docker network ls: List Docker NetworksHow docker network ls works: listing networks, the default bridge/host/none, filtering, and debugging connect… docker network rm: Remove Networks & In-Use ErrorsHow docker network rm works: deleting user-defined networks, the active-endpoints error, prune, and CI cleanu… docker run: Usage, Options & Common CI ErrorsHow docker run works: starting a container from an image, port and volume mapping, env vars, --rm cleanup, an… docker compose up: Start Services & CI ErrorsHow docker compose up works: starting all services from a compose file, detached mode, --build, --wait, and t…