Cloudflare DDNS Updater with Dual-ISP IPv4 & IPv6 Support

中文

This Bash script automatically updates a Cloudflare DNS record with your current public IP addresses, including support for:

• IPv6
• Dual IPv4 addresses from two ISPs (ISP1 and ISP2)

It is intended for home servers or self-hosted services using Cloudflare for DNS and having multiple external IPs (e.g., from dual-WAN routers or multiple broadband providers).

✨ Features

• Supports both A (IPv4) and AAAA (IPv6) records.
• Supports two distinct IPv4 addresses (e.g., dual ISP environments).
• Works with dynamic IP addresses.
• Simple and easily customizable.

⚙️ Requirements

• A Cloudflare API token with DNS edit permissions.
• Pre-existing DNS records in Cloudflare (one AAAA and two A records).
• curl, jq, and host command-line tools installed.

🛠️ Configuration

Edit the script variables:

API_TOKEN="your_cloudflare_api_token"
zoneid="your_zone_id"
dnsrecord="your.full.domain.com"

dnsrecordid6="record_id_for_AAAA"
dnsrecordid4_isp1="record_id_for_ISP1_IPv4"
dnsrecordid4_isp2="record_id_for_ISP2_IPv4"

Set IP information source URLs (optional):

IPV6_INFO_SOURCE="https://6.ipw.cn"
IPV4_INFO_SOURCE="http://myip.ipip.net"

Update ISP keywords in the script (ISP1, ISP2) to match your actual provider labels (e.g., "China Telecom", "China Unicom").

🚀 Usage

Make the script executable and run:

chmod +x ddns-update.sh
./ddns-update.sh

You can add it to a cron job for automatic updates:

crontab -e
# Run every 10 minutes
*/10 * * * * /path/to/ddns-update.sh

🔐 Security Notes

• Do not share your API token or zone ID.
• Consider storing sensitive values in environment variables or a .env file and loading them in the script.

🧾 License

MIT License.