How to set up Dynamic DDNS with Google Domains and Freenas

. Friday, March 20, 2020

Part 1: Have a (leased) Google Domains domain.
Part 2: Set up a DDNS Record. Souce

Setting up a Dynamic DNS synthetic record

  1. Sign in to Google Domains.
  2. Select the name of your domain.
  3. Open the menu Menu.
  4. Click DNS.
  5. Scroll down to Synthetic Records.
  6. Select Dynamic DNS from the list of synthetic record types.
  7. Enter the name of the resource you plan to have assigned a Dynamic IP, either a subdomain or @ for your default domain (“root domain” or “naked domain”).
  8. If you selected a sub-domain, enter the name of the subdomain.
  9. Click Add.
  10. The Dynamic DNS record is created in your list of synthetic records. Click the expand triangle next to the record to view its values.
  11. Click View Credentials to view the user name and password created for this record.
  12. Note the username and password created for the synthetic record. You'll need these to configure your gateway or client software to contact the Google name servers.
You can edit or delete the record with the Edit and Delete buttons next to the record.
Part 3: Setting up Freenas: 
This is for more common config where Freenas does not connect to the internet directly, but behind NAT firewall
Start Dynamic DNS service. Check Start on boot.
Open wrench icon to configure it as such:
Don't check CheckIP Server SSL
CheckIP server:
CheckIP server path: /
DO Check use SSL below
Domain name: see FQDN of the record you've set up in part 2
Username/Password - not your google account, but DDNS subdomain updating username/password - provided after creating it and CAN be looked at afterward.
Fill or select fields in yellow as shown:

Update 2024: RIP Google Domains.