(1) A forward proxy is located in front of the client and is used to send requests to other servers on the Internet. It can provide anonymity and is usually used in internal networks to control network access rights.
(2) A reverse proxy is located in front of one or more web servers and intercepts requests from the Internet. It is mainly used for load balancing, network acceleration, and as a protection layer for security and anonymity.
(3) Open Proxy allows users to connect to and use a proxy server, usually for anonymous browsing and bypassing content restrictions.
(4) Transparent Proxy does not modify requests and responses when forwarding them, but is visible to the client. Often used for caching and content filtering.
(5) Anonymous Proxy can be identified as a proxy server, but does not reveal the original IP address. Used for anonymous browsing.
(6) Distorting Proxy provides the target server's incorrect original IP address, similar to Anonymous Proxy, but intentionally provides false IP information.
(7) Elite Proxy is difficult to detect as a proxy server. These proxies do not send X-Forwarded-For or other identifying headers, thereby achieving maximum anonymity.
The most commonly used types of proxies are forward proxy and reverse proxy.
Forward Proxy
A forward proxy is an intermediary between the client and the server. It sits between the client (such as a computer in an internal network) and the external server (such as an Internet website).
When a client makes a request, it is first sent to the forward proxy. The proxy decides whether to allow, modify, or block the request based on its configuration and rules.
One of the main functions of a forward proxy is to hide the client's IP address. When it forwards the request to the target server, the target server thinks the request came from the proxy server itself.
This provides users with a degree of anonymity, which is particularly suitable for privacy protection or bypassing IP-based restrictions or monitoring.
Forward proxy usage scenarios
(1) Instagram Proxy This is a specific type of forward proxy used to manage multiple Instagram accounts without triggering blocks or restrictions. Marketers, social media managers, and influencers use Instagram proxies to pretend to be in a different region or user in order to manage multiple accounts, automate tasks, or collect data without being flagged for suspicious activity.
(2) Web Usage Control and Monitoring Organizations use forward proxies to monitor and control employee web usage, block access to non-work-related websites, ensure compliance with organizational policies, and protect networks from web-based threats.
(3) Cache frequently used content A forward proxy can also cache frequently accessed content, which means that when multiple users request the same content, the proxy can serve the content directly from its cache instead of getting it from an external server each time, thereby increasing loading speeds and reducing bandwidth consumption. This is particularly beneficial on networks with expensive or limited bandwidth.
(4) Anonymize Web Access Individuals with privacy concerns can use a forward proxy to hide their IP address and other identifying information, making it difficult for websites to track their browsing activities.
Reverse Proxy
A reverse proxy is a type of proxy server that sits in front of one or more web servers and intercepts client requests before they reach the server.
Unlike a forward proxy, which hides the identity of the client, a reverse proxy actually hides the identity of the server or the existence of multiple servers behind it. The client only interacts with the reverse proxy and may not be aware of the existence of the backend server.
It distributes client requests across multiple servers, thus load balancing and ensuring that no single server is overloaded. This is critical to maintaining high availability and reliability.
In addition, a reverse proxy can compress incoming and outgoing data, cache files, and manage SSL encryption, which can speed up load times and reduce server load.
From the client's perspective, they appear to be communicating directly with the target server. The client sends a request to a specific web address, and the reverse proxy forwards that request to the appropriate backend server.
Typical examples of reverse proxies
(1) Load Balancers Distribute incoming network traffic to multiple servers, ensuring that no single server is overloaded and preventing any server from becoming a bottleneck. Load balancers can be thought of as a type of reverse proxy designed specifically for load distribution between servers.
(2) Content Distribution Network (CDN) CDNs are a network of servers that provide cached static content based on the user's geographic location. They act as reverse proxies, fetching content from the original server and caching it so that it is closer to the user, thereby enabling faster delivery.
(3) Web Application Firewall (WAF) A WAF sits in front of a web application, inspecting incoming traffic to block hacker attacks and filtering bad traffic, while protecting the application from common web vulnerabilities.
(4) SSL Offloading/Acceleration Some reverse proxies handle the encryption and decryption of SSL/TLS traffic, offloading this task from the web server to optimize performance.
