I posed this question to tech support, who should be able to answer it, since it's a supported product. But they bailed instead.
I'm confused about the use of https://members.sonic.net/connections/fusion/ipv6/. I'm trying to set up IPv6—specifically 6rd, since that seems to be the most you offer. I've configured my Linux router per http://www.litech.org/6rd/ and can, surprisingly, ping6 and traceroute6 to ipv6.google.com.
What I don't understand then is what this page is for. I thought that I had to enable 6rd in order to use it. But when I go to the page, it says "We're sorry, but we were unable to find a supported managed IPv6 capable modem associated with this service address."