DDNS

DDNS (Dynamic Domain Name System) simplifies connection to your Synology NAS over the Internet by mapping a hostname to its IP address. For example, DDNS allows you to access your Synology NAS using a domain name (e.g., www.john.synology.me) without needing to remember an IP address (e.g. 172.16.254.1).

Setting up DDNS

You can point an existing hostname at the IP address of your Synology NAS, or register for a new one provided by Synology or several other DDNS providers. Please consult each provider for more details regarding hostname registration.

To set up a DDNS hostname:

1. Go to Control Panel > External Access > DDNS.
2. Click Add.
3. A dialog box appears prompting you to edit the following settings:
   • Service provider: Select a service provider. To register for a free hostname provided by Synology, choose Synology from the drop-down menu.
   • Hostname: Enter a registered DDNS hostname, such as john.synology.me.
   • Username/Email: Enter the username/email for your DDNS provider.
   • Password/Key: Enter the password/key for your DDNS provider.
   • External address: Enter the external IP address of the Synology NAS which will use the hostname.
4. Click Test Connection to see if settings are correct.
5. If you select Synology as the service provider, you can configure the following settings:
   • Get a certificate from Let's Encrypt and set it as default: Tick the checkbox to apply a Let's Encrypt SSL certificate for your Synology DDNS and set it as the default certificate for DSM. However, if an SSL certificate is already matched for your DDNS hostname, the checkbox will be disabled. For more information on the SSL certificate, please refer to this article.
   • Enable Heartbeat: Tick the checkbox to receive alerts regarding the status of the mapped hostname.
6. Click OK to save and finish.

After setup is complete, you can access your Synology NAS over the Internet by entering the DDNS hostname in a web browser.

Managing Hostnames

Use the following buttons to manage existing hostname entries:

• Delete: Removes the selected hostname entry from the list.
• Edit: Change settings of the selected hostname entry.
• Update Now: Updates the status of all hostname entries which have DDNS service enabled.

Setting up a Customized DDNS Provider

You can add a customized DDNS service provider if your provider does not already appear in the service provider list.

To set up a customized DDNS provider:

1. Go to Control Panel > External Access > DDNS.
2. Click Customize Service Provider.
3. A dialog box appears prompting you to enter the following settings:
   • Service Provider: Enter the name of your customized service provider.
   • Query URL: Enter the URL of your customized service provider.
4. Click Save to add the customized service provider to the list of DDNS service providers.