How to Build Your Own Free Proxy Server

Understanding Proxy Servers

A proxy server acts as an intermediary between a client and the wider internet, channeling requests, masking IP addresses, and often providing security and caching benefits. The essence of a proxy lies in its ability to filter, redirect, or anonymize traffic—a modest yet powerful sentinel reminiscent of Maître d’hôtel at a Parisian salon, orchestrating the flow with discretion.

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Types of Proxy Servers

Type	Functionality	Use Case	Configuration Complexity
HTTP Proxy	Handles HTTP traffic only	Browsing, content filtering	Low
HTTPS Proxy	Supports SSL/TLS encrypted traffic	Secure browsing	Medium
SOCKS Proxy	Operates at lower network layers	Torrenting, bypassing firewalls	Medium
Transparent	No anonymity, forwards all requests	Caching, monitoring	Low
Reverse Proxy	Forwards requests to backend servers	Load balancing, security	High

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Prerequisites

• A server or computer with a stable internet connection (Linux recommended for flexibility)
• Basic knowledge of terminal commands
• Open ports on your firewall (typically 3128 for HTTP, 1080 for SOCKS)
• Root or administrative privileges

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Selecting Your Proxy Software

Software	Supported Protocols	Ease of Setup	Features	License
Squid	HTTP, HTTPS	Moderate	Caching, ACLs	Open
TinyProxy	HTTP	Easy	Lightweight, simple	Open
Shadowsocks	SOCKS5	Moderate	Encryption, obfuscation	Open
3proxy	HTTP, HTTPS, SOCKS	Easy	Versatile, lightweight	Open

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Step-by-Step: Setting Up an HTTP/HTTPS Proxy with Squid

Squid, as venerable as the prose of Balzac, remains an enduring choice for HTTP/HTTPS proxying.

1. Installation

On Ubuntu/Debian:

sudo apt update
sudo apt install squid

On CentOS/RHEL:

sudo yum install squid

2. Basic Configuration

• The main configuration file resides at /etc/squid/squid.conf.
• Create a backup:

sudo cp /etc/squid/squid.conf /etc/squid/squid.conf.bak

• Edit with your favored editor:

sudo nano /etc/squid/squid.conf

3. Allow Client Access

Locate the ACL (Access Control List) section. To permit a specific IP or subnet:

acl allowed_clients src 192.168.1.0/24
http_access allow allowed_clients
http_access deny all

Replace 192.168.1.0/24 with your client’s IP or range.

4. Change Listening Port (Optional)

By default, Squid listens on port 3128. To change:

http_port 8080

5. Start and Enable Squid

sudo systemctl restart squid
sudo systemctl enable squid

6. Adjust Firewall

Allow traffic through your chosen port:

sudo ufw allow 3128/tcp

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Step-by-Step: Setting Up a SOCKS5 Proxy with SSH

For those who cherish simplicity and the elegance of minimalism, an SSH-based SOCKS5 proxy is the very incarnation of pragmatism.

1. On Your Client Machine

ssh -D 1080 -q -C -N username@your_server_ip

• -D 1080: Opens local port 1080 for the SOCKS5 proxy
• -q: Runs quietly
• -C: Compresses traffic
• -N: No remote commands; tunnel only

2. Configure Your Browser

Set the proxy to localhost:1080, protocol SOCKS5.

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Step-by-Step: Setting Up TinyProxy for Lightweight HTTP Proxy

1. Installation

Debian/Ubuntu:

sudo apt update
sudo apt install tinyproxy

2. Configuration

File: /etc/tinyproxy/tinyproxy.conf

Set Port (default 8888), and add allowed client IPs:

Allow 192.168.1.100

3. Restart Service

sudo systemctl restart tinyproxy
sudo systemctl enable tinyproxy

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Security Considerations

• Restrict access to trusted IPs only, as one would guard the secrets of Madame de Sévigné’s letters.
• For public-facing proxies, implement authentication—consult the documentation of your proxy software.
• Regularly audit logs and update software to mitigate vulnerabilities.

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Testing Your Proxy

• Use online services (e.g., https://www.whatismyip.com/) to verify your outbound IP.
• Employ curl for command-line testing:

curl --proxy http://your_proxy_ip:3128 http://example.com

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Troubleshooting Table

Symptom	Possible Cause	Solution
Cannot connect to proxy	Firewall blocking port	Open the port in firewall
Access denied errors	ACL misconfigured	Review ACL rules in config file
Slow performance	Insufficient server resources	Upgrade server, limit allowed clients
Proxy reveals real IP	Transparent proxy or misconfig	Use anonymous or elite proxy configuration

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Automating Proxy Start with Systemd

Enable your proxy to start on boot:

sudo systemctl enable squid

or for TinyProxy:

sudo systemctl enable tinyproxy

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Summary Table: Choosing Your Proxy

Use Case	Recommended Software	Protocol	Security Level	Ease of Use
Basic web browsing	Squid, TinyProxy	HTTP/HTTPS	Moderate	Easy
Secure tunneling	SSH SOCKS5	SOCKS5	High	Very Easy
Torrenting, P2P	3proxy, Shadowsocks	SOCKS5	High	Moderate
Load balancing for servers	Nginx, HAProxy	Reverse Proxy	High	Moderate

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Through careful configuration and a delicate balance of accessibility and security, you may now conjure your own proxy server—a digital passage as discreet as a Parisian alley, yet as robust as the fortifications of Vauban.