Explanation of three proxy servers and reverse proxy

1. Standard Proxy Cache)
A standard proxy cache is usually used to store static web pages (HTML, image) on a machine on the local network ). When this page is requested again, the browser will directly obtain it from the local proxy cache instead of from the source web server. The browser is explicitly configured to use the proxy server. All HTTP requests direct to the proxy server cache, rather than the web server. The cache directly satisfies the request (when the request is stored in the cache again) or forwards the request to the target server.

2. Transparent Proxy Server (transparent cache)
A transparent proxy has the same functions as a standard proxy, but it is transparent to browser operations. The browser does not need to explicitly configure the proxy server. Instead, the transparent proxy intercepts network communication and filters out HTTP Communication at 80. If the filtered request exists in the cache of the transparent proxy server, it will be directly responded to by the cache; if the cache does not exist, the package will be sent to the target server. In Linux, the transparent proxy intercepts network communication through iptables and ipchains. The transparent proxy is widely used by ISPs (Internet Service Provider) because they need a mode set without a browser. At the same time, the transparent proxy server is also a simple way to create a cache for the LAN, because it does not need the external equivalent cache.

3. Reverse Proxy Server (reverse proxy cache)
The reverse proxy server is different from the standard proxy server and transparent proxy server. It is mainly used to reduce the load of the web server, rather than to reduce the load of the client's network bandwidth traffic. The reverse proxy server can cache the static content of the web server to protect the server against unexpected overload. The reverse proxy server is between the Internet and the Web server and controls all requests to reach the web server. The reverse proxy server intercepts all requests to the Web server and responds to the cached content. This method reduces the actual response of a large number of web servers to improve the web efficiency.

The following article describes how to use Apache to configure the reverse proxy server.

Apache is the world's No. 1 web server software. It can run on almost all widely used computer platforms. Because of its wide use of cross-platform and security, it is one of the most popular web server software. Apache, as a reverse proxy server (R-proxy), can be integrated with was, WLS, and so on, but cannot be integrated with IIS.

Generally, port ing is required for servers accessing the Intranet over the Internet. For example, the IP address of the route is 192.168.0.1, And the IP address of Intranet server a is 192.168.0.2.

To allow the Internet to access the Web page of server a through a route, you must set TCP port 80 ing on the route. Transfer the Internet access to the Internet IP address TCP 80 to the TCP port 80 of 192.168.0.2 of server. In this way, accessing the Internet (that is, the Internet)'s Internet ip http 80 web page is to access the TCP 80 HTTP web service of server a 192.168.0.2.

If a second server B or a wants to open another port, a different port must be allocated to the corresponding port on the route.

Then, if there are more than two servers in the LAN, for server a to install Apache for web services (both Win32 and Unix systems), set the route to map port 80 to. For other server B and server C, you can install Apache, IIS, or other possible HTTP service software. You do not need to perform port ing on the route or use specific ports for the web service.

You can even install another Web service software on server a to use a port other than port 80. Then, the key content is to set Apache on server a and implement a reverse proxy, this allows the Internet to access other server web pages of server a on the same LAN through the Web proxy provided by Apache of server.

I am using apache2.2.17

First, install Apache. Download the Apache installer from the http://www.apache.org and double-click the installer to install it. After installation, a red feather icon will appear in the system tray at the bottom right of the screen, which is the Apache control program. Click this icon to start the Apache server. Open IE and enter it in the address bar of IE.http://localhost/You should be able to see the welcome image of Apache.

After Apache is started properly, you can configure it.

Next, modify the Apache configuration file to support the HTTP Proxy server function. Open in a text editorhttpd.confFile. The file is located in the conf directory of the Apache installation directory. If you do not change the installation path when installing ApacheC:\Program Files\Apache Group\Apache\conf\httpd.conf .

First, add the proxy server module. Find the following lines:

#LoadModule proxy_module modules/mod_proxy.so#LoadModule proxy_connect_module modules/mod_proxy_connect.so#LoadModule proxy_http_module modules/mod_proxy_http.so#LoadModule proxy_ftp_module modules/mod_proxy_ftp.so

Remove the # sign to make the corresponding module take effect.

Then, set one item for each server in the LAN for proxy:

<VirtualHost 192.168.0.2>ServerName www.xxx.comProxyPass / http://192.168.0.3:88/ProxyPassReverse / http://192.168.0.3:88/</VirtualHost>

This part of content can only be addedhttpd.confUnder this file.

Then add the following sentence at the end:

ProxyRequests   On

192.168.0.2It is the IP address of server a, that is, the server used as the Apache proxy.www.xxx.com Is a domain name, which must be resolved to the domain name of the Route Public IP. Whilehttp://192.168.0.3:88Is the Intranet web service address that server a can access. You can specify both the IP address and port.

After the configuration is complete, restart Apache to act as the reverse proxy service.

Reference link: Wikipedia-Proxy Server

 

Reprinted from: http://blog.darkmi.com/2012/10/25/2441.html thanks to the original author to share!

Explanation of three proxy servers and reverse proxy