What Is a Proxy? Forward, Reverse, and Transparent Proxies

A proxy is an intermediary that processes network requests between a client and a server. It is used for anonymization, caching, filtering, load balancing, and SSL termination. The 3 main types are forward proxies (outbound internet access), reverse proxies (inbound service access), and transparent proxies.

Types

Forward Proxy

• Internal clients → proxy → Internet
• Uses: web filtering, caching, logging, and anonymization
• Examples: Squid, BlueCoat, Cisco WSA

Reverse Proxy

• Internet → proxy → internal servers
• Uses: SSL termination, LB, web caching, and WAF
• Examples: NGINX, HAProxy, Apache, Cloudflare, F5

Transparent Proxy

• No client configuration required (interception)
• Traffic is routed using policy-based routing or WCCP
• Uses: ISP filtering and FW interception

SWG (Secure Web Gateway)

The modern evolution of the forward proxy:

• URL filtering with ML
• Threat detection
• DLP
• Cloud application visibility
• Vendors: Zscaler, Netskope, Symantec (Broadcom), Palo Alto Prisma Access

Modern Features

• SSL decryption
• Authentication (AD integration)
• Bandwidth control
• Compression
• Caching
• Analytics and reporting

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Forward and reverse proxies: Squid, NGINX, and F5. Migration to SWG/SASE. Quote within 48 hours.