问题：nginx: [emerg] socket() [::]:80 failed (97: Address family not 
supported by protocol)

解决方案

vim /etc/nginx/conf.d/default.conf 
将 
listen 80 default_server; 
listen [::]:80 default_server;

改为： 
listen 80; 
#listen [::]:80 default_server;

重新启动nginx即可，网上说的那种kill掉nginx进程和ipv6 on的方法不适用