My ISP gives dynamic public ipv6 and private ipv4, hence I have to enable IPV6 feature, and add IPv6 Firewall Rules to allow public connection to one of the device in the network, with the help of ddns service.

Everything works perfectly, until the connection being refreshed, a new IPV6 prefix will be assigned, then the firewall rules will not going to work anymore. 

The dns updated with new address, but it is no longer connectable because the firewall rules still having the old IPv6 address.

It would be great if the firewall rules reference the device by using fixed MAC address or some already existing identifying method used to verifying if it is the same device. So that I do not have to always going into the administration UI to

1. edit all the existing rules, click on "VIEW CONNECTED DEVICES",

2.selected the device with the same device name / mac address",

3.click save to close the dialog.
 

then it will start working again.