HTTP_HOST：bbs.newswan.net

 HTTP_X_REAL_IP：121.18.236.247

 REMOTE_ADDR：202.204.175.60
==============================
 HTTP_HOST：bbs.uibe.edu.cn

 HTTP_X_REAL_IP：

 REMOTE_ADDR：121.18.236.247
==============================
bbs上为了是得到经过newswan代理后的客户端ip，newswan代理的时候需要设置

server {

    listen 80;

    server_name bbs.newswan.net www.newswan.net newswan.net;

    location / {

        proxy_pass   http://bbs.uibe.edu.cn;

        proxy_set_header        Host $host;

        proxy_set_header        X-Real-IP $remote_addr;

        proxy_set_header        X-Forwarded-For $proxy_add_x_forwarded_for;

    }

}