Does url resolve support ipv6?

[speedfirst]

I have several upstream servers, which are configured like this:

upstream backend {
  ip_hash;
  server   backend1.example.com;
  server   backend2.example.com;
  server   backend3.example.com  down;
  server   backend4.example.com;
}

each server has ONLY IPv6 address. But seems nginx can't parse it to
that address, and report an error like this "[error] host not found".

Is this a bug or meant not to be supported yet?

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,177146,177146#msg-177146