The iperf3 utility can be downloaded here.
The commands listed below should be entered via terminal or command prompt. Sync should be shut down completely on both peers during the tests.
On one machine start iperf3 as server, listening to a certain port
iperf3 -s -p 9000
-s - run as a server,
-p 9000 - listen to a port 9000 (put the Sync's listening port of that peer instead of 9000).
On the second machine, start iperf3 as client
Running as client iperf3 will connect to a listening iperf3 server and measure the peer-to-peer network performance. The 4 commands below are to be executed sequentially, each after the previous one is finished:
iperf3 -c XXX.XXX.XXX.XXX -p 9000
iperf3 -c XXX.XXX.XXX.XXX -p 9000 -R
iperf3 -c XXX.XXX.XXX.XXX -p 9000 -u -b 100M
iperf3 -c XXX.XXX.XXX.XXX -p 9000 -u -b 100M -R
-c - run as a client,
XXX.XXX.XXX.XXX - the IP address of your first (iperf3 server) machine,
9000 - the iperf3 server listening port. It must be the same for the server and client; "9000" - is here for example purpose only, choose the port as described above,
-u - use UDP instead of TCP,
-b 100M - use the bandwidth of 100 mbit/s for UDP tests (the value should not exceed the ISP-provided bandwidth),
-R - "reverse mode" (server will send data to the client).
After finishing the test, copy the complete terminal output, including the commands typed, from both the iperf3 server and the client terminals. Paste it to a text file on each side and send these to the Resilio support team.