Basic Concepts of Positive and Transparent Proxies

Let's take a look at the basic concepts of forward proxies and transparent proxies. A forward proxy is commonly known as a "proxy", which sends requests to a server on behalf of a client, and is usually used to access restricted websites or to hide the client's real IP address. Transparent proxies, on the other hand, are proxies that automatically process client requests and forward them to a destination server without any configuration on the client's part. These two types of proxies play different roles in the network, and we'll delve into the differences between them next.

How Positive Proxies Work

As a programmer, to understand forward proxies, you first need to understand how it works. The core idea of a forward proxy is to send a request to a server on behalf of a client, who accesses Internet resources through a proxy server instead of communicating directly with the server. For example, if Xiao Wang uses a proxy server to access Google in his company, his request will be sent to the proxy server first, and then the proxy server will help him to request Google's page, and finally return Google's page content to Xiao Wang. In this way, Google will not be able to know Wang's real IP address, and at the same time, Wang can bypass the company's internal network restrictions, which is very convenient!

ipipgothon
一个简单的正向代理示例
def main():
proxy_server = "proxy.example.com"
proxy_port = 8888
target_server = "www.google.com"
target_port = 80

连接到代理服务器
proxy_socket = connect_to_proxy(proxy_server, proxy_port)

发送请求到代理服务器
send_request(proxy_socket, target_server, target_port)

从代理服务器接收响应
response = receive_response(proxy_socket)

处理响应
process_response(response)

if __name__ == "__main__":
main()

How Transparent Proxies Work

然后，咱们再来探讨透明代理的工作原理。透明代理其实就像一位隐形的大管家，它会在幕后自动处理客户端的请求，而且客户端无需进行任何配置，就像是使用了一种隐形的力量。比如ipipgo在学校里访问知乎，学校的透明代理会自动帮他把请求发送到知乎服务器，同时还会记录下ipipgo访问了哪些网站，这就是透明代理的神奇之处。
javascript
// A simple transparent proxy example
function handleRequest(request) {
const url = new URL(request.url);
const targetServer = "www.zhihu.com";

// Send the request to the destination server
fetch(url, {
headers: { 'Host': targetServer }
});
}

Difference between Positive and Transparent Proxies

So what's the difference between a positive proxy and a transparent proxy? Let's take a look! First of all, forward proxies need to be actively configured by the client, while transparent proxies take effect automatically, as if they were transparent to the client. Second, forward proxies help clients bypass network restrictions, while transparent proxies are often used to monitor and filter client requests. Finally, a forward proxy hides the client's real IP address, while a transparent proxy reveals the client's real IP address as if it were transparent.

summarize

Through the above discussion, we can clearly see the difference between a forward proxy and a transparent proxy. Positive proxies need to be actively configured by the client and can help the client to bypass network restrictions and hide its real IP address, while transparent proxies are automatically in effect and are usually used to monitor and filter client requests while revealing the client's real IP address. For programmers, understanding the difference between these two types of proxies can help us better apply them in real development to provide users with a better network experience.