From Project Segfault Wiki

Iperf3 is a tool which can be used to measure how fast your connection to our servers is.

We run iperf3 instances on all our nodes.

To test, run the following:

# Replace anything between the brackets with the data provided in the table below.
iperf3 -p [ port ] -c [ address ] # Upload
iperf3 -R -p [ port ] -c [ address ] # Download

There can only be one connection to the server at a time with iperf3.

Server Address Port
Pubnix p.projectsegfau.lt 5202
Pizza1 pizza1.projectsegfau.lt 5201
IN Node in.projectsegfau.lt 5201
US Node us.projectsegfau.lt 5201