In this guide, you’ll learn how to assign a static IP address to a Docker container using a custom bridge network. This IP address will remain fixed even after your host system reboots.

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✅ Why You Need This

By default, Docker assigns dynamic IPs to containers via its bridge network. If you restart your server or container, the IP may change — which breaks networking for apps relying on fixed addresses.

This tutorial helps solve that by:

• Creating a custom bridge network
• Assigning a fixed IP
• Enabling auto-restart after reboot

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🧰 Prerequisites

• Docker installed on your Linux system (docker -v to verify)
• Root or sudo access

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🔧 Step 1: Create a Custom Bridge Network

The default Docker bridge does not support static IP assignment. So, first create a custom one:

docker network create \
  --driver bridge \
  --subnet 192.168.100.0/24 \
  --gateway 192.168.100.1 \
  my_custom_bridge

✅ This creates a new Docker bridge network:

• Subnet: 192.168.100.0/24
• Gateway: 192.168.100.1
• Name: my_custom_bridge

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🚀 Step 2: Run a Container with a Static IP

Now, start your container with a fixed IP and auto-restart policy:

docker run -dit \
  --name my_httpd \
  --network my_custom_bridge \
  --ip 192.168.100.10 \
  --restart unless-stopped \
  httpd
Code language: CSS (css)

✅ This ensures:

• 192.168.100.10 is always assigned
• The container restarts after reboot
• It uses your custom bridge

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🔄 Step 3: Test Persistence After Reboot

Reboot your host system:

sudo reboot

After the reboot, run:

docker ps
docker inspect my_httpd | grep IPAddress

✅ You should see your container up and running with the same IP.

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📝 Additional Notes

• Avoid IP conflicts by managing assigned IPs manually.
• You can replace httpd with any image (e.g., nginx, mysql, your-custom-app).
• Use docker network inspect my_custom_bridge to check connected containers.

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🧠 Bonus Tip: Docker Compose Version

Create a docker-compose.yml:

version: '3.7'
services:
  web:
    image: httpd
    container_name: my_httpd
    restart: unless-stopped
    networks:
      mynet:
        ipv4_address: 192.168.100.10

networks:
  mynet:
    driver: bridge
    ipam:
      config:
        - subnet: 192.168.100.0/24
          gateway: 192.168.100.1
Code language: JavaScript (javascript)

Then run:

docker-compose up -d

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✅ Conclusion

You’ve now:

• Created a custom Docker network
• Assigned a static IP to a container
• Ensured it persists across reboots

This is especially helpful for microservices, reverse proxies, and apps that require stable internal networking.

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