Znail is a network emulator inteded to run on a Raspberry Pi. Equipped with two network interfaces, the Raspberry Pi acts as a network bridge. Znail can then control network traffic passing through the bridge.
With a system under test connected to the network through this bridge, Znail can help you answer question about how that system behaves under various network conditions.
- Emulate packet delay
- Emulate packet loss
- Emulate packet duplication
- Emulate packet reordering
- Emulate packet corruption
- Control packet rate
- Capture network packets
- Emulate a disconnect (by powering down one of its network interfaces)
- Override answers to DNS queries (by redirecting DNS traffic to its internal DNS server)
- Redirect IP traffic from one host to another
- Not apply any of the above for certain hosts using a whitelist
Znail can be managed in one of two ways, using its web interface or its REST API.
The easiest way to get started with Znail is to generate a Rasbian image with Znail pre-installed.
A virtual machine is used to build the image.
Vagrant and the vagrant-scp plugin is required.
To set up the environment on recent Ubuntu systems, run the following commands:
sudo apt update
sudo apt install vagrant
vagrant plugin install vagrant-scp
To generate an image:
make image
The resulting image can be found in the dist/image directory.
The image can then be installed on a Raspberry Pi.
The Python environment requires that the pip tool is installed.
To set up the development environment on recent Ubuntu systems, run the following commands:
sudo apt update
sudo apt install python3-pip python3-venv
To build and activate the virtual Python environment:
source ./activate
To automatically format the code:
make format
To run tests and static code analysis:
make check
More information about what targets the build system provides:
make help
Special thanks to Alice Persson for contributing the Znail logotype.
Distributed under the terms of the Apache License 2.0.