Divided into three categories: client agent, intermediate link agent, server agent
1. Client Agent
1. Standard Agent
It is a proxy service running on the web client. A standard proxy buffer service is used to cache static web pages to a host on the local network (ie, a proxy server). When the cached page is accessed for the second time, the browser will directly obtain the request data from the local proxy server instead of requesting the data from the original web site (at this time, the http request message is still sent to the corresponding web server, Only the http response is redirected to get locally). Can save network bandwidth and improve access speed.
Illustration: 1. The HTTP requests 1 and 2 in the figure are the same except for the IP address that initiated the request.
2. The web response content is cached by the proxy server. When the PC initiates the same request again, the cached content is directly responded to the PC, which belongs to the local area network transmission and does not go through the public network
2. Transparent proxy
It is a proxy service running on the web client. The proxy operation is transparent to the client browser, that is, it is not necessary to specify the IP and port of the proxy server. The transparent proxy server blocks network communication and filters out HTTP (port 80) traffic to the outside. If the client's request is buffered locally, the buffered data is sent directly to the user. If there is no buffer, the proxy server sends a request to the remote web server, and the request response is cached to the proxy server and sent to the client. It can save bandwidth more than standard proxy, and can reduce the access to the web server, and can improve the access speed better.
Second, the intermediate link agent
3. Server Agent
1. Reverse proxy
Is a proxy service running on the web server,