其实根据nginx的wiki的表述,在linux下一般默认的监听ipv6的一个端口会同时把ipv4的端口相应地监听起来。除非自己手动设置了/proc/sys/net/ipv6/bindv6only为1。今天重新编译了nginx后发现在ipv4环境下blog不能访问了，但是ipv6环境下是可以正常访问的。就单独搞了一下原来的配置是listen [::]:443 ssl so_keepalive=on;listen [::]:80 so_keepalive=on;
listen [::]:443 ssl so_keepalive=on ipv6only=on spdy;
listen 443 ssl so_keepalive=on spdy;
listen [::]:80 so_keepalive=on ipv6only=on;
listen 80 so_keepalive=on;