1.配置如下

server {
        listen       80;
        server_name  localhost;
		
		large_client_header_buffers 4 16k;
        client_max_body_size 300m;
        client_body_buffer_size 128k;
        proxy_connect_timeout 600;
        proxy_read_timeout 600;
        proxy_send_timeout 600;
        proxy_buffer_size 64k;
        proxy_buffers   4 32k;
        proxy_busy_buffers_size 64k;
        proxy_temp_file_write_size 64k;

        location / {
            root   html;
            index  index.html index.htm;
        }
		
		location /project {
			allow	220.178.25.22;
			allow	172.2.2.0/24;
			allow	192.2.2.0/24;
			deny	all;
            proxy_pass http://172.2.2.20:8080/project/;
            proxy_set_header   Host    $host:$server_port;
            proxy_set_header   X-Real-IP   $remote_addr; 
            proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
			client_max_body_size    10m;
        }

        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
    }
 

以上配置的作用是允許IP為220.178.25.22，以及172和192網段的機器可以訪問這個location地址，其他IP的客戶端訪問均是403。

其中，24是指子網掩碼為255.255.255.0。

3.對照表(子網掩碼/CIDR值)

255.0.0.0/8
255.128.0./9
255.192.0./10
255.224.0./11
255.240.0./12
255.248.0./13
255.252.0./14
255.254.0./15
255.255.0./16
255.255.128/17
255.255.192/18
255.255.224/19
255.255.240/20
255.255.248/21
255.255.252/22
255.255.254/23
255.255.255/24
255.255.255.128/25
255.255.255.192/26
255.255.255.224/27
255.255.255.240/28
255.255.255.248/29
255.255.255.252/30