What is linktester?


linktester is a small link test application that uses iperf3 and ethtool to look for errors, problems on a network link. You could use it for example to test a new physical connection between a new card you installed on a server and an existing machine.

How does it work

The way is works is simple:

  • Capture statistics on the card using ethtool
  • Wait for a remote iperf3 server to start. Once is up, send TCP traffic to trigger for a few minutes any unwanted behaviour.
  • Capture statistics on the card using ethtool a second time and compare error counters
  • Report back


  • iperf3 and iperf3 libraries (most distributions have RPM, DEB packages)
  • Python3
  • Rest of the dependencies will be installed with PIP and a virtual environment: rich, python3-iperf3

For example, on Fedora (or any RPM based system) you can install the dependencies as follows:

sudo dnf -y install iperf3 python3-ethtool libnl

On a Debian based distribution:

sudo apt-get install -y python3-ethtool iperf3

Virtual environment

I do recommend you use a virtual environment for the installation:

python3 -m virtualenv $HOME/virtualenv/linktester
. $HOME/virtualenv/linktester/bin/activate

For the rest of the installation instructions I will assume you have activated your virtual environment as explained above.


Once all the base bindings are installed then you can proceed to install from Pypi.org:

pip install linktester


If you want to contribute features you can do this:

python3 -m virtualenv $HOME/virtualenv/linktester
. $HOME/virtualenv/linktester/bin/activate
git clone git@github.com:josevnz/linktester.git
python setup.py develop


Please report any bugs on the official linktester page


Here is a tutorial that comes with the code