iperf3 is an open-source tool used to measure network bandwidth and analyze connection performance. With iperf3, we can perform real-time network speed tests between two devices. Install iperf3 Installing iperf3 on the client and server. Debian/Ubuntu sudo apt install iperf3 CentOS/RHEL sudo dnf install iperf3 Firewall Configuration iperf3 uses port 5201. Ensure this port is open on the server so the client can connect. If using ufw as the firewall, open port 5201 with the following command: ...