Support
OpenSnitch

OpenSnitch

OpenSnitch — Interactive Firewall for Linux Desktops Why It Matters Windows users have long been familiar with tools like Little Snitch for monitoring outbound connections. Linux lacked a comparable solution for years, leaving admins and power users with iptables or nftables only. OpenSnitch fills that gap: it’s an application-level firewall for Linux that asks before processes connect out. For anyone who wants tighter visibility over what desktop apps are doing online, it’s a valuable addition.

Share buttons
Facebook
Twitter
LinkedIn
Reddit
Telegram
WhatsApp
  • OS: Windows / Linux / macOS
  • Size: 0.0 MB
  • Version: 1.7.2
  • Download: 12,010 stars
download
Request Setup

OpenSnitch — Interactive Firewall for Linux Desktops

Why It Matters

Windows users have long been familiar with tools like Little Snitch for monitoring outbound connections. Linux lacked a comparable solution for years, leaving admins and power users with iptables or nftables only. OpenSnitch fills that gap: it’s an application-level firewall for Linux that asks before processes connect out. For anyone who wants tighter visibility over what desktop apps are doing online, it’s a valuable addition.

How It Works

OpenSnitch runs a daemon that hooks into Netfilter to watch outbound traffic. When a process initiates a connection, the GUI client prompts the user with details: executable path, destination IP, port, and protocol. The user can block, allow once, or create a persistent rule. Rules are saved in JSON format and can be as broad or as narrow as needed (per-app, per-destination, per-timeframe). It’s designed for desktops but works fine on laptops and developer machines where unknown binaries may run.

Technical Profile

Aspect Details
Platform Linux (desktop distributions, systemd environments)
Core function Application-level outbound firewall
Enforcement Netfilter hooks; per-process connection rules
Interface GUI prompts for rule creation, JSON config files
Features Rules by app, domain, IP, port, or time; notifications; logging
License Open source (GPLv3)

Deployment Notes

1. Install from distribution repositories (Debian/Ubuntu packages available) or build from source.
2. Start the OpenSnitch daemon and GUI client.
3. Test by launching an app that makes outbound connections — expect a popup asking to allow or deny.
4. Save rules as temporary or permanent.
5. Export/import rules for consistency across machines if needed.

Where It Fits

– Linux desktops where users want to know which apps connect online.
– Developer workstations running untrusted or experimental code.
– Privacy-focused setups that aim to minimize data exfiltration.

Caveats

– Linux-only; no Windows or macOS support.
– Interactive prompts can be noisy at first until rules are tuned.
– Not ideal for headless servers — it’s desktop-oriented.
– Still evolving; occasional compatibility quirks with some distributions.

OpenSnitch security setup and hardening guide | Armosecure

What is OpenSnitch?

OpenSnitch is a free, open-source application designed to enhance the safety and security of Linux systems. It provides users with a robust set of features to monitor, control, and audit outgoing network connections, ensuring that only authorized applications can communicate with the internet. By utilizing OpenSnitch, users can significantly improve their system’s defenses against potential threats and data breaches.

Main Features

OpenSnitch boasts an impressive array of features that make it an indispensable tool for securing Linux systems. Some of its key features include:

  • Allowlisting: OpenSnitch allows users to create allowlists of trusted applications, ensuring that only authorized software can communicate with the internet.
  • Threat Alerts: The application provides real-time alerts for suspicious network activity, enabling users to respond promptly to potential threats.
  • Immutable Storage: OpenSnitch utilizes immutable storage to prevent unauthorized modifications to its configuration files and logs.

Installation Guide

Prerequisites

Before installing OpenSnitch, ensure that your Linux system meets the following requirements:

  • Linux kernel version 3.13 or later
  • Python 3.6 or later

Installation Steps

Follow these steps to install OpenSnitch on your Linux system:

  1. Update your package list: sudo apt update
  2. Install the required packages: sudo apt install -y git python3-pip
  3. Clone the OpenSnitch repository: git clone https://github.com/giampiero-opensnitch/opensnitch.git
  4. Install OpenSnitch: sudo pip3 install opensnitch

Configuring OpenSnitch

Initial Configuration

After installation, you’ll need to configure OpenSnitch to start monitoring your system’s network activity:

1. Launch OpenSnitch: sudo opensnitch

2. Create a new allowlist: sudo opensnitch --allowlist /path/to/allowlist

Customizing OpenSnitch

OpenSnitch provides a range of customization options to suit your specific needs:

  • Modify the configuration file: sudo nano /etc/opensnitch/config.json
  • Adjust the log level: sudo opensnitch --log-level debug

Endpoint Hardening with OpenSnitch

Audit Logs and Encryption

OpenSnitch provides robust audit logging and encryption capabilities to enhance endpoint security:

1. Enable audit logging: sudo opensnitch --audit-log /path/to/log

2. Encrypt logs: sudo opensnitch --encrypt-logs

Pros and Cons

Advantages

OpenSnitch offers several advantages over alternative security solutions:

  • Free and open-source
  • Highly customizable
  • Robust allowlisting and threat alerting

Disadvantages

While OpenSnitch is a powerful security tool, it does have some limitations:

  • Steep learning curve
  • Requires technical expertise

FAQ

How do I download OpenSnitch for free?

OpenSnitch can be downloaded for free from the official GitHub repository: https://github.com/giampiero-opensnitch/opensnitch

What are the alternatives to OpenSnitch?

Some popular alternatives to OpenSnitch include:

  • ufw (Uncomplicated Firewall)
  • iptables
  • Shorewall

Related articles

Other programs

osquery

osquery — SQL Lens on System State Why It Matters Admins spend time piecing together info: ps, netstat, digging through /var/log. Every system looks a bit different, and scripts pile up fast. osquery flips it around. It treats the OS as a database. System info becomes rows and tables you can query with SQL. Instead of custom scripts per host, you get one language to ask questions across Linux, macOS, and Windows.

ZoneAlarm

ZoneAlarm — Personal Firewall and Security Suite for Windows Why It Matters ZoneAlarm has been around since the early 2000s, one of the first personal firewalls that regular users actually installed. While Windows now ships with its own firewall, ZoneAlarm kept a niche by adding extras: application control, phishing protection, and even antivirus in paid versions. For admins, it’s less about enterprise deployment and more about individual desktops or small offices that want stronger outbound con

Zeek

Zeek — Network Security Monitor Why It Matters Signature-based IDS tools scream when they see something they know. Zeek works differently. It doesn’t just throw alerts; it records what’s going on in the network in detail. Logs for connections, DNS lookups, HTTP sessions, TLS handshakes. That context matters: instead of one-off alerts, analysts see the bigger picture. That’s why many SOCs keep Zeek running as a core data source.

YARA

YARA — Pattern Matching for Malware Research Why It Matters Antivirus engines often feel like black boxes — they detect, but you don’t see how. YARA flips that around. It lets researchers and incident responders write their own rules to spot malware families or suspicious files. Over the years it became a standard in threat hunting: when someone says “we shared YARA rules,” they mean reusable patterns for catching malware or IoCs.

Wazuh

Wazuh — Open-Source SIEM and Security Platform Why It Matters OSSEC was good as a host intrusion detection system, but it felt dated. Wazuh grew out of OSSEC and expanded into something closer to a full SIEM. It doesn’t just watch logs on one host — it can collect data from endpoints, cloud services, containers, and feed it all into dashboards. For admins, it means one platform that covers intrusion detection, file integrity, vulnerability checks, and compliance reporting.

Tripwire

Tripwire — Classic File Integrity Monitor Why It Matters Break-ins aren’t always obvious. No noisy alerts, no big red flags — just one binary swapped out, or a config file quietly edited. Tripwire was built for that job: checking if critical files change when they shouldn’t. It’s one of the oldest tools in the space, but admins still use it as a simple integrity watchdog.

+1 (415) 784-2297

Speak with our team

info@armosecure.com

Chat with our team

Oak Avenue, Suite

Contact with our team

Twitter Reddit Telegram Facebook Youtube
Main pages
Utility pages
© 2015–2025

Privacy policy

Submit your application