pfSense

When creating or updating a DDNS entry using "GoDaddy (v6)" as the service, the following entries appear in the system logs when verbose logging is enabled:

Aug 23 11:49:00 php-fpm 18000 /services_dyndns_edit.php: Dynamic DNS: updatedns() starting
Aug 23 11:49:00 php-fpm 18000 /services_dyndns_edit.php: Dynamic DNS godaddy-v6 (host.domain.com): 2001:xxxx:yy:zzz::a extracted from local system.
Aug 23 11:49:00 php-fpm 18000 /services_dyndns_edit.php: Dynamic DNS (host.domain.com): running get_failover_interface for opt2. found gif0
Aug 23 11:49:00 php-fpm 18000 /services_dyndns_edit.php: Dynamic DNS godaddy-v6 (host.domain.com): _update() starting.
Aug 23 11:49:00 php-fpm 18000 /services_dyndns_edit.php: Dynamic DNS godaddy-v6 (host.domain.com): _checkStatus() starting.
Aug 23 11:49:00 php-fpm 18000 /services_dyndns_edit.php: phpDynDNS (host): PAYLOAD:
Aug 23 11:49:00 php-fpm 18000 /services_dyndns_edit.php: phpDynDNS (host): (Unknown Response)

The entry is not created or updated on GoDaddy's end, and the cache data for the entry in pfSense shows ::

The regular "GoDaddy" service for IPv4 works fine.

And yes, I realize that the address of my GIF0 interface isn't going to change... it's the only external IPv6 interface I have at the moment, and when my ISP starts supporting IPv6 via DHCP-PD, I want to make sure DDNS will be working too. I use the hostname to do ping availability/latency checks from an outside host.