Forward proxy and reverse proxy are two common proxy modes in network and server architecture, and they play an important role in network communication and security. Understanding their differences is crucial for networking professionals as well as ordinary users. This article will delve into the definition, difference and role of forward proxy and reverse proxy

1.What is a forward proxy

Forward proxying is when the proxy server sends requests to the internet server on behalf of the client. In this case, the client accesses Internet resources through a forward proxy server rather than connecting directly to those resources. Typical applications of forward proxies include accessing restricted websites, protecting client privacy, and breaking through access restrictions.

For example, when users in mainland China cannot directly access certain foreign websites, they can access these websites by connecting to forward proxy servers located in other countries, because the proxy server can "initiate requests on behalf of" the user while protecting the user. real IP address.

2.What is a reverse proxy

A reverse proxy means that the proxy server receives and processes requests from clients on behalf of the server. In this case, clients think they are communicating directly with the proxy server, when in fact the proxy server forwards the request to one or more backend servers and returns the received response to the client. Reverse proxies are often used for load balancing, security protection, and hiding backend servers.

For example, when a user visits a website, they actually send a request to a reverse proxy server rather than connecting directly to the backend server where the website's content is hosted. The reverse proxy server forwards requests to different backend servers based on load conditions to ensure website stability and performance.

3.The difference and function of forward proxy and reverse proxy

a.Service objects

The forward proxy is a proxy for the client, and the server does not know who the real client is; while the reverse proxy is a proxy for the server, and the user does not know who the real server is.

b.Erection location

The forward proxy is set up between the client and the target host; the reverse proxy server is set up on the server side.

c.effect

The forward proxy is mainly used to solve access restriction problems, and the reverse proxy is mainly used to solve problems such as load balancing and security protection.

3. Application scenarios of forward proxy and reverse proxy

a.Forward proxy

Access previously inaccessible resources, such as certain blocked websites or services.

Do caching to speed up access to resources. When the user accesses the same information again, the information is directly taken out from the buffer and passed to the user to improve the access speed.

Authorize client access and authenticate online. The proxy can record user access records (online behavior management) and hide user information from the outside.

Resolve access restriction issues. Through the proxy server, you can break through your own IP access restrictions and access foreign websites, etc.

b.Reverse proxy

It is mainly used in the case of distributed deployment of server clusters to hide intranet server information, protect and hide intranet servers.

The intranet can use clusters, and the proxy can be configured at the same time and play a load balancing role.

Provides buffering services for servers with slow backends. The reverse proxy server can provide caching services for static content and dynamic content with a large number of access requests in a short period of time, improving access speed.

Provide security. The reverse proxy server can be used as an application layer firewall to provide websites with protection against web-based attacks (such as DoS/DDoS), making it easier to detect malware, etc. It can also provide unified encryption and SSL acceleration (such as SSL terminal proxy) for back-end servers, and provide HTTP access authentication, etc.