While designing infrastructure solutions, Proxies are utilized in different ways.
– Forward Proxy [ Egress Proxy ]
– Reverse Proxy [ Ingress Proxy ]
Forward Proxy vs Reverse Proxy:
Key Differences
Proxy servers act as intermediaries between clients and servers, but their direction of service determines whether they are forward or reverse proxies.
Forward Proxy:
A Forward Proxy is a type of proxy server that sits between a client and a server, acting as an intermediary for requests from the client to the server. It’s called a “forward” proxy because it forwards requests from the client to the server.
Key Characteristics:
- Client-initiated: The client initiates a request to the Forward Proxy, which then forwards it to the server.
- Server-agnostic: The client doesn’t know the details of the server; it only knows the Forward Proxy’s address.
- Request forwarding: The Forward Proxy forwards the client’s request to the server, and then returns the server’s response to the client.
- Anonymity: The client’s IP address is hidden from the server, as the request appears to come from the Forward Proxy’s IP address.
- Caching: Forward Proxies can cache frequently accessed resources, reducing the load on the server and improving response times.
Here are some product examples of Forward Proxies:
- Squid: A popular open-source Forward Proxy caching server for web traffic.
- Apache HTTP Server with mod_proxy: A widely used web server that can be configured as a Forward Proxy.
- NGINX: A web server and reverse proxy server that can also function as a Forward Proxy.
- HAProxy: A high-performance load balancer and Forward Proxy server.
- F5 BIG-IP: A comprehensive application delivery controller (ADC) that includes Forward Proxy capabilities.
- Cisco Web Security Appliance (WSA): A security-focused Forward Proxy for web traffic.
- Blue Coat ProxySG: A secure web gateway that functions as a Forward Proxy.
- IBM DataPower Gateway: A purpose-built appliance that includes Forward Proxy capabilities (as mentioned earlier).
- Microsoft Forefront TMG (Threat Management Gateway): A discontinued but still used Forward Proxy server.
- Pulse Secure: A secure access solution that includes Forward Proxy capabilities.
- Glabal Protect (Prisma): A secure access solution that includes Forward Proxy capabilities.
These products can be used in various scenarios, such as:
- Content filtering and caching
- Load balancing and application delivery
- Security and threat protection
- Access control and authentication
- Web acceleration and optimization
Note that some of these products may offer additional features beyond Forward Proxy capabilities.
Web Proxy vs SOCKS Proxy:
Key Differences
Both web proxies and SOCKS proxies act as intermediaries between clients and servers, but they differ in their protocol support, functionality, and use cases.
Web Proxy:
HTTP/HTTPS protocol support only: designed specifically for web traffic
Understands web requests: can interpret and modify HTTP headers, cookies, and content
Caching and content filtering: can cache frequently requested resources and filter out unwanted content
Typical use cases: anonymous browsing, content filtering, caching, and accessing geo-restricted websites.
SOCKS Proxy:
SOCKS proxy servers redirect traffic through them before passing it on to the intended destination. This is achieved by first establishing a TCP connection with the proxy server through the SOCKS protocol.
Data can then be sent from your computer to the proxy server, which then relays it to the recipient
Multi-protocol support: handles various protocols like HTTP, HTTPS, FTP, SMTP, and more
Does not interpret traffic: simply forwards packets without modifying or caching content
Better suited for non-web traffic: ideal for applications like email, FTP, and torrent clients
Typical use cases: anonymous torrenting, accessing geo-restricted content, and bypassing firewalls
Reverse Proxy:
Server-side proxy: sits between servers and the internet
Hides server IP addresses: protects servers from direct access, improving security
Load balancing: distributes incoming requests across multiple servers
SSL termination: handles SSL encryption and decryption, reducing server load
Caching and compression: improves performance and reduces bandwidth usage
Typical use cases: server protection, load balancing, content delivery networks (CDNs)
Reverse Proxy:
A Reverse Proxy is a server that sits between a server and a client, acting as an intermediary for requests from the client to the server. It’s called a “reverse” proxy because it reverses the typical proxy flow, where the proxy sits between the client and the internet.
Key Characteristics:
- Server-initiated: The server initiates the connection to the Reverse Proxy, which then forwards requests to the client.
- Client-agnostic: The server doesn’t know the details of the client; it only knows the Reverse Proxy’s address.
- Request forwarding: The Reverse Proxy forwards the client’s request to the server, and then returns the server’s response to the client.
- Server protection: The Reverse Proxy hides the server’s IP address and protects it from direct client access.
- Load balancing: Reverse Proxies can distribute client requests across multiple servers to improve responsiveness and availability.
Flow:
- Client sends request to Reverse Proxy
- Reverse Proxy forwards request to Server
- Server processes request and sends response to Reverse Proxy
- Reverse Proxy returns response to Client
Benefits:
- Security: Protects server from direct client access and attacks
- Scalability: Enables load balancing and server scaling
- Flexibility: Allows for server maintenance and updates without affecting clients
- Caching: Can cache frequently accessed resources to improve performance
- SSL termination: Can handle SSL encryption and decryption, reducing server load
Common Use Cases:
- Web servers: Protect and load balance web servers
- API gateways: Manage and secure API traffic
- Microservices: Enable communication between microservices and clients
- Cloud services: Provide a single entry point for cloud-based services
DataPower as a Reverse Proxy:
IBM DataPower can be configured as a Reverse Proxy to provide advanced security, scalability, and performance features, such as:
- Security: Authentication, authorization, and encryption
- Load balancing: Distribute client requests across multiple servers
- Caching: Cache frequently accessed resources
- SSL termination: Handle SSL encryption and decryption
- Content routing: Route requests based on content type or URL
By using DataPower as a Reverse Proxy, organizations can protect their servers, improve scalability and performance, and provide a secure and flexible infrastructure for their applications.