Hey there, that error crops up when Docker attempts to assign a subnet to a new network that’s already occupied—whether by another Docker network, your host machine’s local network, or even an active VPN connection. Let’s break down the fixes step by step:

Step 1: Identify the conflicting subnet #

First, you need to pinpoint which network is causing the overlap:

• List all Docker networks with:

  docker network ls
  

• Inspect each network to check its subnet (replace <network-name> with the actual name from the list):

  docker network inspect <network-name>
  

  Look for the "Subnet" field in the output—this will show you the IP range the network is using.
• Also check your host’s active networks:
  • Linux/macOS: Run ip addr
  • Windows: Run ipconfig
    Compare these ranges to the one Docker is trying to use for your my_project to spot the overlap.

Step 2: Resolve the conflict #

Choose the fix that fits your scenario:

Option 1: Delete the conflicting Docker network #

If the overlap is with a custom Docker network you no longer need (or can reconfigure):

• Stop any containers using that network:

  docker stop <container-name>
  

• Delete the conflicting network:

  docker network rm <network-name>
  

• Restart your my_project—Docker will either auto-assign a non-conflicting subnet, or you can specify one manually (see Option 2).

Option 2: Specify a custom subnet in your docker-compose.yml #

If you’re using Docker Compose for my_project, explicitly define a subnet that doesn’t overlap with existing networks. Add this to your docker-compose.yml:

networks:
  default:
    ipam:
      config:
        - subnet: 192.168.200.0/24

Pick a range like 192.168.xxx.0/24 or 172.30.xxx.0/24—avoid common default Docker ranges like 172.17.0.0/16 or 172.18.0.0/16.

Option 3: Reset Docker’s default network (for default bridge conflicts) #

If the overlap is with Docker’s default bridge network, you’ll need to reset it (note: this will wipe all existing Docker networks and containers, so back up data first):

• Stop the Docker service:
  • Linux: sudo systemctl stop docker
  • macOS: Quit Docker Desktop from the menu bar
  • Windows: Stop the Docker Desktop Service via Services, or quit from the system tray
• Delete Docker’s network database (Linux only):

  sudo rm -rf /var/lib/docker/network/files/local-kv.db
  

  For macOS/Windows, use Docker Desktop’s "Reset to factory defaults" option under Settings > Troubleshoot.
• Restart Docker, then launch your my_project again.

Option 4: Check for VPN conflicts #

If you’re running a VPN, it might be using the same subnet as Docker. Try temporarily disconnecting the VPN, starting your project, then reconnecting. If that works, adjust your VPN’s subnet settings to avoid the overlap.

内容的提问来源于stack exchange，提问作者bruna_dosti