How to Set Up Dynamic DNS with Cloudflare

How to Set Up Dynamic DNS with Cloudflare

Dynamic DNS (DDNS) is a crucial tool for anyone hosting services at home. Since most residential internet connections have dynamic IP addresses that change periodically, accessing your home server or other devices remotely becomes a challenge. DDNS solves this by automatically updating a DNS record with your current public IP address, allowing you to connect using a consistent hostname. Cloudflare, a popular DNS and security provider, offers a free DDNS service that’s easy to set up. Here’s a detailed guide:

1. Prerequisites:

• A Cloudflare Account: If you don’t already have one, sign up for a free account at cloudflare.com.
• A Domain: You’ll need a domain managed by Cloudflare. If you don’t have one, you can register one through Cloudflare or transfer an existing one.
• A DDNS Update Client: You’ll need a program on your local network that detects IP address changes and updates Cloudflare. Popular options include:
  • cloudflare-ddns (Recommended): A lightweight and versatile command-line client.
  • Online DDNS Updaters: Some routers have built-in DDNS update functionality.
  • Custom Scripts: You can create your own script using Cloudflare’s API.

2. Identify Your Zone ID and DNS Record:

• Log in to your Cloudflare account.
• Select the appropriate domain.
• Navigate to the “DNS” tab.
• Locate the A record you want to update. If you haven’t created one yet, create a new A record with your desired subdomain (e.g., home.yourdomain.com) and point it to a placeholder IP address (e.g., 1.1.1.1). Take note of the Name (your subdomain) and the Zone ID which can be found in the right-hand sidebar under “Zone ID.”

3. Setting Up cloudflare-ddns (Recommended Method):

• Installation: cloudflare-ddns is available for various operating systems. Installation instructions can be found on its GitHub repository. For example, on Debian/Ubuntu systems:
  bash
sudo apt install cloudflare-ddns

• Configuration: Edit the configuration file, usually located at /etc/cloudflare-ddns/config.json:
  json
{
"domain": "yourdomain.com",
"zone-id": "YOUR_ZONE_ID",
"token": "YOUR_API_TOKEN",
"records": [
{
"type": "A",
"name": "home",
"proxied": false // Set to true if you want Cloudflare to proxy the connection
}
]
}

  • Replace "yourdomain.com" with your actual domain.
  • Replace "YOUR_ZONE_ID" with the Zone ID you obtained earlier.
  • Replace "home" with the subdomain you are using for DDNS.

• Generating an API Token:

  • In your Cloudflare dashboard, go to “My Profile” -> “API Tokens.”
  • Click “Create Token.”
  • Select the “Edit zone DNS” template.
  • Under “Zone Resources,” select “Include,” then choose your domain and set permissions to “Edit.”
  • Click “Continue to summary” and then “Create Token.”
  • IMPORTANT: Copy the generated token immediately. You won’t be able to view it again. Paste it into your config.json file as "YOUR_API_TOKEN".

• Running the Client:
  bash
sudo systemctl enable cloudflare-ddns # To start on boot
sudo systemctl start cloudflare-ddns

4. Using Other DDNS Clients:

Refer to your router’s documentation or the chosen DDNS client’s instructions for configuration. You’ll typically need to provide your domain/subdomain, the Zone ID or API Key from Cloudflare, and potentially other details.

5. Verification:

After setting up the client, check your Cloudflare DNS records after a few minutes. The A record for your subdomain should reflect your current public IP address. Try accessing your home server using the hostname you configured.

Troubleshooting:

• Check Logs: Examine the logs of your DDNS client for any error messages.
• Verify API Token: Ensure the API token has the correct permissions and is correctly entered in the configuration.
• Firewall Rules: Confirm your firewall allows outbound connections on the ports used by the DDNS client (usually port 80 or 443).

By following these steps, you can successfully set up Dynamic DNS with Cloudflare, ensuring reliable access to your home network resources regardless of IP address changes. Remember to keep your DDNS client running and periodically check your Cloudflare DNS records to ensure everything is functioning correctly.