IPmon Autor: Libor Benes

IPmon is a privacy-first Firefox extension that provides real-time passive monitoring of all remote IPv4 addresses and URLs your browser connects to. Designed for security professionals, developers, and privacy-conscious users.

Passive Monitoring Approach:
IPmon uses Firefox's API to passively observe (sniff) network connections without interfering with or modifying any traffic. It has read-only access to connection metadata (IPs, URLs, timestamps) and cannot block, redirect, or tamper with your network requests.

Features:
• Real-time Monitoring: Watch as IPv4 connections are made while you browse.
• Complete Connection Details: View IP addresses, full URLs, domains, and timestamps.
• Easy Data Management:
• Copy individual IP addresses with one click.
• Copy all IPs (one per line) for analysis.
• Copy all connection data (formatted with spacing).
• Export complete logs as text files.
• Smart Filtering: Automatically excludes private IPs (192.168.x.x, 10.x.x.x, 127.0.0.1, etc.).
• Persistent Storage: Connection history saved across browser sessions.
• Sidebar Interface: Always-visible monitoring without interrupting your workflow.
• Privacy-First: No data collection, no tracking, no telemetry.

Ideal For:
• Security Professionals: Monitor for suspicious connections during incident response.
• Network Administrators: Understand browser network behavior and dependencies.
• Web Developers: Debug API calls and third-party dependencies.
• Privacy Advocates: See exactly which servers your browsing contacts.
• Students: Learn about web infrastructure and network protocols.
• CTF Participants: Capture connection patterns during security challenges.

Privacy and Security:
• No Data Collection: Explicit declaration in manifest - "none" required.
• Local Processing: All data stays in your browser, never transmitted.
• Minimal Permissions: Only to monitor connections, for persistence and export.
• Secure Implementation: Safe DOM methods only. Input validation. No vulnerable features.
• Transparent: Open-source approach with clear functionality.

How It Works:
• Opens as a sidebar for continuous monitoring.
• Captures IPv4 connections via Firefox's webRequest API.
• Filters out private/local IP addresses.
• Displays connections in reverse chronological order (newest first).
• Stores up to 2000 entries with automatic cleanup.
• Provides multiple export options for analysis.

IPmon pairs perfectly with these networking extensions:
• IP Geolocator: Find geographic locations for captured IPs.
• IP Now: Display your current public IP addresses.

Technical Details:
• Firefox 109.0+ compatible.
• WebExtensions API (Manifest v3).
• 100% client-side processing.
• Works offline after installation.
• 58KB total extension size.

Note: Some connections may not be captured due to Firefox's privacy protections (DNS-over-HTTPS, tracking protection, etc.). This extension shows what Firefox reveals to web extensions, respecting user privacy settings.