Iperf is a tool used for network testing, typically by creating TCP and UDP data streams to measure network performance.
The latest version, iperf3, has been completely rewritten and is not compatible with the original version.
Installation
For Ubuntu or Debian, you can use the following command:
# apt install iperf3Usage:
You need to use one device as the server and another as the client. Run this command on the server:
# iperf3 -s -p 9220
And this command on the client (replacing the IP parameter with the appropriate address depending on whether you are testing a private network or a VPN):
# iperf3 -c IP -p 9220
Results:
Once the two devices are linked, the output will look similar to the screenshot, with several key points to consider.
- Interval: The time span between checks.
- Transfer: The amount of data transferred during the interval.
- Bitrate: The speed of the transfer.
The same tabs as in the previous section are displayed, with additional fields for Retr and Cwnd.
- Retr: Represents retransmitted TCP packets and indicates the number of TCP packets that had to be resent; the lower the number, the better.
- Cwnd: Represents the Congestion Window . The congestion window is a TCP state variable that limits the amount of data TCP can send to the network before receiving an ACK.
Installation
For RHEL-based distributions such as CentOS or Rocky Linux, you can use the following command:
# dnf install iperf3
Usage:
You need to use one device as the server and another as the client. Use the following command for the server (you can change the port in both commands, but ensure it does not conflict with another active service):
#iperf3 -s -p 9220And the command for the client (replacing the IP parameter with the appropriate address depending on whether you are testing a private network or a VPN):
#iperf3 -c IP -p 9220Results:
Once the two devices are linked, the output will look similar to the screenshot, with several key points to consider.
- Interval: The time span between checks.
- Transfer: The amount of data transferred during the interval.
- Bitrate: The speed of the transfer.
The same tabs as in the previous section are displayed, with additional fields for Retr and Cwnd.
- Retr: Represents retransmitted TCP packets and indicates the number of TCP packets that had to be resent; the lower the number, the better.
- Cwnd: Represents the Congestion Window . The congestion window is a TCP state variable that limits the amount of data TCP can send to the network before receiving an ACK.
Installation
For Windows, you need to download iperf3. Once downloaded, unzip the file.
Usage:
After unzipping the file, execute it from a CMD terminal. Once CMD is open, navigate to the directory where the file is located. If you are using the same user and the file is in Downloads, you can use the following command:
#cd DownloadsOnce you are in the same directory, execute the file. You need to use one device as the server and another as the client, and run the following command for the server (you can change the port in both commands, but ensure it does not conflict with another active service):
#iperf3.exe -s -p 9220And the command for the client (replacing the IP parameter with the appropriate address depending on whether you are testing a private network or a VPN):
#iperf3.exe -c IP -p 9220Results:
Once the two devices are linked, the output will look similar to the screenshot, with several key points to consider.
- Interval: The time span between checks.
- Transfer: The amount of data transferred during the interval.
- Bitrate: The speed of the transfer.
We hope this helps. Remember, if you have questions about this or any other matter related to your servers on Clouding, contact us at support@clouding.io We’re here to assist you!