2001:0000::/32
Teredo
This is a mapped address allowing IPv6
tunneling through IPv4 NATs. The address is
formed using the Teredo prefix, the server’s
unique IPv4 address, flags describing the type
of NAT, the obfuscated client port and the
client IPv4 address, which is probably a private
address. It is possible to reverse the process
and identify the IPv4 address of the relay server,
which can then be looked up in the relevant
RIR’s Whois database.
You can do this on the following webpage:
http://www.potaroo.net/cgi-bin/ipv6addr