This guide explains how to perform an online speed test using the command line (iPerf CLI) between your computer and your Synology NAS. These tests can help you evaluate the download and upload speeds of your Internet connection to and from your NAS.

Setting up the Speedtest tool

To install the SynoCli Monitor Tools package:

1. From the DSM interface, go to the Package Center.
2. Click on the Settings button in the taskbar, then go to the Package Source tab.
3. Click on the Add button.
4. Fill in the fields as follows:
   • Name: SynoCommunity
   • Location: https://packages.synocommunity.com/
5. Confirm both windows by clicking OK.
6. A new tab called Community will appear in the left-hand menu.
7. Select it, then install the SynoCli Monitor Tools package.

Enabling the SSH connection

To enable the SSH service:

1. In the DSM interface, open the Control Panel.
2. Click on the Terminal & SNMP tab in the left-hand menu.
3. Check the Enable SSH service box.
4. Click Apply to save.
   • If you no longer need the SSH connection after the test, you can uncheck this box to disable the service.

Launching the iPerf server

To connect to the NAS via SSH, use an application like Terminal (command-line interface, CLI) on your device:

1. Run the following command:

   ssh username_dsm@synology_ip

2. Enter the password for your DSM account, then press Enter.

3. Once connected via SSH, start the iPerf server with the following command:

   iperf3 -s

Starting the speed test

To download and run the iPerf3 client:

1. Download the iPerf3 executable for your operating system from the official website.
2. Open a new console.
3. Navigate to the folder where the iPerf3 executable is located.

4. Run the following command:

   iperf3 -c ip_du_synology

5. The test results will be displayed after a few seconds. You can then view the upload and download bandwidth between your computer and your Synology NAS.