Replicating IPv4 LAN configuration with IPv6

My setup consists of a cable modem (provided by my ISP), an ASUS router and several LAN clients. Some of these clients have static IPv4 addresses assigned by the router's DHCP server. Now I activated IPv6 on the ASUS, choosing the 'Passthrough' option as instructed . The clients are assigned addresses according to prefix delegated by the cable modem (in my case 2a02:908:532:bca0::/64). How can I replicate the IPv4 configuration (with static IP addresses for my Synology NAS and Linux server) in this context? The 'Passthrough' setup on the ASUS router does not allow any further configuration, an

Question by janeden on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.