This recipe refers to the regfish DynDNS product and the official script download from the Regfish Help Center. It fits Linux, Unix, and macOS systems that should execute DynDNS updates on their own.

The practical advantage is simple: you use the existing Regfish script bundle instead of maintaining a fully custom DynDNS client yourself.

Prerequisites

• a domain at Regfish
• enabled regfish DynDNS for the target domain
• the matching DynDNS token
• a Linux, Unix, or macOS system with curl
• a scheduler such as cron, systemd timer, or an equivalent mechanism

Step 1: Enable DynDNS and note the token

Enable Dynamic DNS for the target domain in the Regfish management UI and note the generated token.

That token is also required by the official script bundle for authentication.

Step 2: Download the current script bundle from the Help Center

The Help Center currently provides a curl-based DynDNS script bundle. Download the current package from the article DynDNS Client Scripts.

The published filename at the moment is:

regfish.com_dynDNSv2_curl_v3.0.tar.gz

Step 3: Unpack the bundle and place it locally

Store the bundle on the system that should later run the DynDNS updates and unpack it into a dedicated working directory.

tar -xzf regfish.com_dynDNSv2_curl_v3.0.tar.gz
cd regfish.com_dynDNSv2_curl_v3.0

If the package name changes in a later Help Center revision, adjust this step to the then-current download.

Step 4: Apply token and hostname to the local script setup

At minimum, provide:

• the DynDNS token
• the full hostname that should be updated
• the desired IP family or update variant

Apply those values exactly the way the script bundle and its included instructions expect. The purpose of this recipe is not to recreate the bundle, but to place it correctly into a production workflow.

Step 5: Configure recurring execution

Then configure recurring execution so IP changes are reported to regfish DynDNS automatically.

A typical target shape is:

*/5 * * * * /opt/regfish-dyndns/run-update.sh

The important part is not the exact scheduler technology, but that the script runs repeatedly and in a controlled way.

Step 6: Verify the first run and later updates

After the first run, verify:

• that the script exits without errors
• that the target hostname was updated successfully
• that a DynDNS update is visible in the Regfish management UI

If your operations model requires it, add your own logging or monitoring around the script as well.

Practical notes for production setups

• treat the DynDNS token like a credential and do not leave it exposed in shared directories
• separate script files, configuration, and scheduler definitions cleanly
• log exit code and runtime so failures do not go unnoticed
• always prefer the current bundle from the Help Center instead of carrying an old copy forever
• after bundle updates, briefly verify whether invocation or configuration expectations changed

Result

This gives you a lean legacy DynDNS updater based on the official Regfish client scripts. It is especially practical for hosts and small servers that do not use a direct router integration such as a FRITZ!Box.