I have an ADSL modem (Zyxel P660-HN51) that was purchased based on the fact it was advertised as IPv6 ready and my thought was to keep the private IPv4 addresses on the LAN side since many of the devices cannot be setup to use IPv6 and only have an IPv6 address on the WAN side. It appears that this modem cannot do this. I understand the thought is that with IPv6 each device would have its own public IPv6 address but that is not always possible. Are there ADSL modems that do this? I would think this is not a unique configuration.