Using Nginx Proxy Pss IPv4 to IPv6 Problem

[wuweixin]

When do I use nginx reverse proxy to proxy from an IPv4 network to an
IPv6 network, I used the following configuration file:

upstream ipv6server {
    server [2001:: 1];
    server [2001:: 2];
}
location / {
    proxy_pass http://ipv6server;
}

Nginx can start normally, but the start time, when I gave when the HTTP
request, Nginx's CPU usage is particularly high, almost 100%, do not
know why.

I think the current code should support Nginx of IPv4 to IPv6 proxy it,
do not know how to configure for normal use it? Thank you.

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,155900,155900#msg-155900