9.4.2.2 Down Network Removal

Down network removal is the part of docker compose down's overall behavior responsible for removing any networks Compose created for the application — both the automatic default network and any explicitly declared custom networks — as part of the application's teardown.

How Networks Are Removed During Down

Once every service container has been stopped and removed, Compose removes the networks it created specifically for this application.

docker compose down

Removing network myapp_default

This network, automatically created when the application was first brought up, is removed as part of this teardown.

Why Networks Created by Compose Are Safe to Remove

Since these networks exist specifically to support this particular Compose application's services, removing them as part of a full teardown doesn't risk affecting anything outside this application's own scope.

docker network ls

Confirming the network no longer appears validates this part of the teardown completed successfully.

Why External Networks Are Never Removed by Down

A network referenced with external: true is understood to be managed outside this Compose file's scope, and down correctly leaves it untouched, regardless of how thorough the rest of the teardown is.

networks:
  shared-net:
    external: true

docker compose down
docker network ls

This external network remains present after down, since Compose never considered itself responsible for its lifecycle.

Recreating Networks on the Next Up

Since networks Compose created are fully removed by down, a subsequent up simply recreates them fresh, with no lingering state carried over from before.

docker compose up -d

Why Down Network Removal Matters

This network cleanup ensures a Compose application's teardown is genuinely complete, leaving no orphaned networking infrastructure behind, while correctly respecting the boundary around externally managed networks that don't belong to this application's own lifecycle.