So I'm trying the enthusiast test, and I've been using dyndns.org for a domain name (sheeettin.ath.cx), but apparently they don't support IPv6.
I sign up for HE's free DNS, and create sheeettin.com (A and AAAA records). Everything goes fine, but I get NXDOMAIN for everything. "Okay," I think, "the DNS server just cached that when I hit the button before getting it completely working." I change the TTL to 300s, hoping that'll somehow work. A few minutes later, nothing. "Okay," I think again, "it's cached for a while. I'll try again tomorrow."
Twenty-four hours later (give or take) I'm still getting NXDOMAINs unless I explicitly tell dig/nslookup/etc. to use ns1.he.net. Online DNS lookup tools (OpenDNS, dnsstuff.net) report NXDOMAINs as well.
Is there something I'm doing wrong, or should I just wait longer?
It doesn't appear that "sheeettin.com" is registered. HE isn't a DNS registrar. They provide a DNS hosting. You still need to register the domain via a registrar such as Godaddy.
Not GoDaddy (see http://www.nodaddy.com/ for reasons), but any other registrar should be ok. Some are better than others. Not everyone supports IPv6 glue.
BTW:
QuoteNo match for "SHEEETTIN.COM".
>>> Last update of whois database: Mon, 31 May 2010 08:29:47 UTC <<<
Still not registered. Better get to it.