How to fix Error response from daemon: network not found in Docker

First, verify whether the network actually exists:

docker network ls

Look for the network name in the output. If you don't see it, the network needs to be created.

You can also search for a specific network:

docker network ls --filter name=<network_name>

Note: Network names are case-sensitive. "myapp" and "MyApp" are different networks.

If the network doesn't exist, create it:

docker network create <network_name>

For a specific driver (bridge is default):

docker network create --driver bridge <network_name>

If using docker-compose with external networks, create the network before running docker-compose up:

docker network create my_external_network
docker-compose up -d

If you're using docker-compose with external networks, ensure the network exists or change your configuration.

Option 1: Create the external network first:

docker network create my_network

Option 2: Let docker-compose manage the network by removing the external declaration:

# Before (requires pre-existing network)
networks:
  my_network:
    external: true

# After (docker-compose creates the network)
networks:
  my_network:
    driver: bridge

Option 3: Use external with the correct name:

networks:
  my_network:
    external: true
    name: actual_network_name  # Must match exactly

Sometimes Docker shows a network in docker network ls but fails to remove or use it (zombie network). This typically happens after Docker crashes or is forcefully stopped.

Solution: Restart the Docker daemon:

# Linux
sudo systemctl restart docker

# macOS/Windows Docker Desktop
# Restart Docker Desktop from the menu bar/system tray

After restart, the zombie network should be properly removed, and you can create a new one:

docker network create <network_name>

If using docker-compose and the network state is inconsistent, force recreation:

docker-compose down --remove-orphans
docker-compose up --force-recreate -d

For a complete reset including volumes (warning: this deletes data):

docker-compose down --volumes --remove-orphans
docker network prune -f
docker-compose up -d

Old containers may reference networks that no longer exist. Find and remove them:

# List all containers (including stopped)
docker container ls -a

# Remove old containers
docker container rm <container_id>

# Or remove all stopped containers
docker container prune

After removing orphaned containers, you can cleanly recreate your networks and start fresh.