NetLatencyInjector

Lagger is a lightweight Linux utility for injecting artificial network latency using tc netem. Designed for developers, testers, or anyone curious about how their apps behave under lag, it provides an intuitive terminal interface for applying and monitoring delay on any network interface.

Features

• Add custom network delay in milliseconds per interface
• View current delay status of all interfaces at a glance
• Vim-style keyboard navigation
• Simple TUI built in Rust with ratatui

Prerequisites

• Linux system with tc (from the iproute2 package)
• sudo privileges
• Rust toolchain (stable)

Installation

# Clone the repository
git clone https://github.com/ItalianG0urmet/NetLatencyInjector.git
cd NetLatencyInjector

# Build the project
cargo build --release

# Run the tool (requires sudo for tc commands)
sudo ./target/release/lagger
sudo ./target/release/NetLatencyInjector

Usage

Key	Action
j / k	Move selection down / up
Enter	Open delay input for selected interface
Esc	Close input without applying
q	Quit

Select an interface, press Enter, type the desired delay in milliseconds, and confirm with Enter again. The current delay for each interface is shown inline next to its name.

Example commands used internally

Lagger internally wraps standard tc commands like:

tc qdisc replace dev <iface> root netem delay 100ms
tc qdisc show dev <iface>