How to Use GitHub Domcyrus Rustnet for Per Process Network Monitoring

Introduction

Have you ever needed to identify which applications consume the most network bandwidth on your endpoints in real-time? Domcyrus Rustnet offers a specialized solution by combining per process network monitoring with deep packet inspection (DPI) in a sandboxed, cross-platform environment. This terminal-based tool empowers IT administrators and network engineers to gain granular visibility into network traffic, essential for troubleshooting, security audits, and optimizing IT automation workflows.

Rustnet's ability to monitor network activity per process allows pinpointing of bandwidth usage and suspicious connections, complementing endpoint management solutions and reducing the guesswork in network diagnostics.

Do this now: Clone the Rustnet GitHub repository to begin exploring its capabilities locally.

Prerequisites / What You Need

Before you start using Rustnet, ensure your environment meets the following requirements:

Operating System: Supports Linux, macOS, and Windows (via WSL or native builds).
Rust Toolchain: Install Rust (version 1.65 or later) from rustup.rs to compile Rustnet from source.
Network Permissions: Root or Administrator privileges are necessary to capture packets and query process information.
Dependencies: libpcap or equivalent (installed via your package manager, e.g., libpcap-dev on Ubuntu).
Terminal: Compatible terminal emulator with UTF-8 support for displaying Rustnet's interface.

Example: On Ubuntu 22.04, run:

sudo apt update
sudo apt install build-essential libpcap-dev
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Do this now: Confirm your Rust version by running rustc --version and check if libpcap is installed.

Step 1: Clone and Build Rustnet

Start by cloning the repository and building the application:

Clone the repo:

git clone https://github.com/domcyrus/rustnet.git
cd rustnet

Build the project using Cargo:

cargo build --release

The compiled binary will be located at ./target/release/rustnet.

Do this now: Run ./target/release/rustnet --help to verify the installation and explore available commands.

Step 2: Launch Rustnet for Real-Time Monitoring

Rustnet operates in your terminal to display per process network activity with deep packet inspection. To start monitoring:

sudo ./target/release/rustnet

Key features you'll see:

Per Process Traffic: Each line corresponds to a process, showing its name, PID, and network usage.
Packet Details: DPI reveals protocol types (TCP, UDP), ports, and payload summaries.
Live Updating: Traffic stats refresh every second allowing real-time insight.

Example: If firefox is consuming excessive bandwidth, Rustnet highlights its connections and packet details.

Do this now: Identify the top 3 processes with the highest outgoing traffic for your current session.

Step 3: Filter and Inspect Specific Processes

Rustnet supports filtering network traffic per process or protocol:

To monitor a single process:

sudo ./target/release/rustnet --pid 1234

To filter by protocol or port:

sudo ./target/release/rustnet --filter "tcp port 443"

This filtering enables targeted analysis, useful during incident response or performance tuning.

Example: Monitoring SSH sessions via port 22 during a maintenance window.

Do this now: Practice filtering network traffic for your critical service processes using PID or port.

Step 4: Integrate Rustnet with IT Automation Tools

Rustnet can export logs or output in JSON format, facilitating integration with IT automation and endpoint management solutions such as Ansible or SaltStack.

Use the --output json flag:

sudo ./target/release/rustnet --output json > network_log.json

Automate monitoring by scheduling Rustnet runs via cron or systemd timers.
Parse logs with scripts or SIEM tools for alerts.

Example: Trigger an alert if a process exceeds 10Mbps bandwidth for more than 5 minutes.

Do this now: Set up a basic script that runs Rustnet every hour and parses JSON output for anomalies.

Step 5: Utilize Sandboxed Network Monitoring

Rustnet runs in a sandboxed environment, limiting its access to only necessary resources, which enhances security during packet inspection.

Sandboxing reduces risks of exposing sensitive data.
It enables safer deployment on endpoints with strict security policies.

Example: Deploy Rustnet on a Windows machine with Windows Sandbox or Linux container environments to maintain isolation.

Do this now: Explore running Rustnet within a Docker container or sandbox to test isolated monitoring.

Step 6: Compare Rustnet with Other Network Monitoring Tools

Feature	Rustnet	Wireshark	nethogs	tcpdump
Per process monitoring	✔️	❌	✔️	❌
Deep Packet Inspection	✔️	✔️	❌	✔️
Cross-platform	✔️ (Linux, macOS, Windows)	✔️	Linux only	Linux, macOS
Terminal-based	✔️	❌ (GUI-based)	✔️	✔️
Sandboxed execution	✔️	❌	❌	❌
Integration with automation tools	✔️ (JSON output)	Limited	Limited	Limited

Do this now: Evaluate Rustnet against your current monitoring stack for gaps in per process visibility.

Common Mistakes to Avoid

Running without necessary privileges: Without root/admin rights, Rustnet cannot capture network packets or query processes.
Ignoring dependency installation: Missing libpcap or Rust toolchain causes build or runtime failures.
Overlooking sandbox benefits: Running Rustnet without sandboxing exposes endpoints to security risks.
Not filtering traffic: Monitoring all traffic can overwhelm outputs; use filters to focus.
Neglecting automation integration: Manual monitoring limits scalability; leverage JSON exports.

Do this now: Audit your Rustnet setup to confirm you have administrative rights and all dependencies installed.

FAQ

Q1: Can Rustnet monitor encrypted traffic?

Rustnet performs deep packet inspection on unencrypted traffic headers and metadata. It cannot decrypt SSL/TLS but can identify encrypted sessions by ports and handshake data.

Q2: Is Rustnet suitable for Windows environments?

Yes. Rustnet supports Windows natively and via Windows Subsystem for Linux (WSL). However, some features may require elevated permissions.

Q3: How does Rustnet impact system performance?

Rustnet is lightweight but continuous packet capture and DPI can increase CPU usage. Running in sandboxed mode helps contain resource use.

Q4: Can I export Rustnet data for SIEM platforms?

Yes, using --output json you can export logs compatible with most SIEM and log management tools.

Q5: How often is Rustnet updated and maintained?

Rustnet has active releases on GitHub, with version 1.3.0 released recently, indicating ongoing development and community support.

Conclusion

Domcyrus Rustnet offers IT administrators and network engineers a powerful, terminal-based tool for per process network monitoring enhanced by deep packet inspection and sandboxed execution. Its cross-platform support and integration capabilities make it a practical choice for detailed network analysis, performance troubleshooting, and automation workflows.

By following the outlined steps, you can install, configure, and leverage Rustnet to gain precise visibility into network activity at the process level, enabling informed decision-making in endpoint management and network security.

Do this now: Implement Rustnet in a controlled environment to benchmark its monitoring insights against existing tools and assess its fit for your organizational needs.