The QNAP 301w router currently does not support suffix matching in its IPv6 firewall. I hope this feature can be added in future versions, because the IPv6 prefix provided by the ISP keeps changing. By using EUI64 to fix the suffix, you can match the corresponding IPv6 address through the suffix. For example:
::1204:c3ff:fe07:8db4/::ffff:ffff:ffff:ffff matches IPv6 addresses with the suffix 1204:c3ff:fe07:8db4.
This method is supported by ip6tables. After connecting via SSH, the following command works:
ip6tables -I USER_FIREWALL 1 -p tcp -d ::1204:c3ff:fe07:8db4/::ffff:ffff:ffff:ffff --dport 20080 -j ACCEPT
However, currently, entering this format directly on the web page does not work.

