四层代理比较方便、简单，nginx.conf 如下

#user  nobody;
worker_processes  1;

#error_log  logs/error.log;
#error_log  logs/error.log  notice;
#error_log  logs/error.log  info;

#pid        logs/nginx.pid;


events {
    worker_connections  1024;
}


stream {    
    #9501 端口将以4层TCP协议方式转发至后端app_sever;
    server {
        listen 9501;                          
        proxy_pass app_server;
    }
    upstream app_server{
        server 172.16.0.248:9511;
        #server 172.22.0.45:30028;
    }

    #代理socket
    server {
        listen 9301;
        proxy_pass socket_server;
    } 
    upstream socket_server{ 
        server 172.16.0.248:9311; #发布socket1服务端
    }
    
    #代理FTP
    server {
        listen 8666;
        proxy_pass ftp_server;
    } 
    
    upstream ftp_server{
        server 172.16.0.248:21; #FTP要设成被动模式，指定端口范围（大于>1024)，配置防火墙，否则会被防火墙拦截
    }
}

 

FTP 被动模式配置

Nginx 四层代理配置_TCP