What are the differences between forward proxy and reverse proxy

Forward proxy and reverse proxy are two common types of proxy IP. There are some differences between them in the location of proxy server, proxy object and application scenario.

1. Forward proxy:

Forward proxy is a kind of proxy server located between the client and the target server. It plays an important role in proxy IP application. In a forward proxy, the client sends a request to the proxy server and explicitly specifies the target server. The proxy server acts as the representative of the client, sends the request to the target server on behalf of the client, obtains the response, and then returns the response content to the client. Such a proxy process makes the client's access to the target server appear as if it were a direct request to the target server.

Ii. Reverse proxy:

A reverse proxy is a proxy server type corresponding to a forward proxy. In reverse proxy, for the client, it directly accesses the proxy server, without specifying a specific target server. In the background, the proxy server forwards client requests to the corresponding target server according to certain rules and policies. The target server is invisible to the client. The clients do not know which target server they are accessing, but in fact, they are accessing different servers.

3. Differences:

Different proxy objects:

In the forward proxy, the proxy server acts on behalf of the client, and the client sends requests to the proxy server. In addition, the address and port of the target server must be specified. The proxy server sends a request to the target server on behalf of the client and returns the response from the target server to the client.

The typical application scenario of forward proxy is to provide access to the Internet on the LAN within the firewall. Assume that client A on the LAN needs to access server C on the Internet, but client A cannot access server C directly due to firewall restrictions. In this case, you can deploy A forward proxy server B on the LAN and allow client A to access proxy server B. Client A sends a request to proxy server B, specifying the target server C to be accessed. After receiving the request, proxy server B sends the request to server C on behalf of client A and returns the response from server C to client A. In this way, client A can indirectly access server C and realize the access to the Internet.

Reverse proxy is the opposite of forward proxy, the object of the proxy is the target server. For the client, it accesses the reverse proxy server and does not need to specify a specific target server. The reverse proxy server forwards client requests to the corresponding target server according to certain rules and configurations. The target server is invisible to the client.

①Five ways to optimize the efficiency of crawlers

One of the typical application scenarios of reverse proxies is load balancing. In a load-balanced architecture, the client sends requests to the reverse proxy server without caring about the specific target server. The proxy server forwards the requests to multiple target servers according to the load balancing algorithm, so as to realize the diversion of requests and improve the concurrent processing capability and performance of the system. Clients access the reverse proxy server in the same way that they directly request the target server, but in reality, they are accessing a different server.

Different usage scenarios:

The forward proxy provides access to the Internet on the LAN within the firewall. For example, client A can access proxy server B and proxy server B can access server C, but client A cannot directly access server C. In this case, proxy server B can be used to forward client A's request to server C.

The most common application scenario of reverse proxies is load balancing. For example, the user accesses the reverse proxy server Nginx, and the proxy server behind it is multiple Tomcat servers. Specific services and static resources are deployed on the Tomcat server. User access to Nginx does not know which Tomcat server to access, but in fact the effect of access is the same, you can receive data feedback.

②Five functions of reverse proxies

In general, forward proxy and reverse proxy have different roles and purposes in the application of proxy IP. A forward proxy is a representative of the client, helping it access other servers, while a reverse proxy is a representative of the target server, helping the client access the server's proxy server. Understanding the differences between the two agents allows you to better apply them to meet different needs and scenarios.