How to SpeedTest LAN Traffic on Windows and Linux Clients and Servers

How to SpeedTest LAN Traffic on Windows and Linux Clients and Servers

Testing your Local Area Network (LAN) speeds on a regular basis is a good idea to make sure you don’t have any major issues that have crept into the network. I would recommend a couple different free tools to use to accurately test every machine on your network. Below will be a brief explanation of each of the solutions followed with instructions and possible issues you might run into.

Windows clients and servers can be tested using Totusoft’s LAN Speed Test which could also be used to test Window’s clients that have network shares to Linux servers. The application is extremelly simple but will provide a nice basic overview of the speeds your LAN is capable of. The application writes a file to any network share, clears the file cache, and then reads the file back to make sure its not reading the file from cache instead of writing it over the network.

Linux clients and servers can be tested using a combination of iperf and ntop both of which can be installed via yum on CentOS. The iperf application can also be used to test against iperf servers over the Internet to see what your WAN bandwidth equates to. If you are running it on your local network it will require two Linux servers, one to run the iperf listener and the other to run as the iperf client. The ntop application is a quick and easy way to provide graphical results for not only ntop but all network traffic.

Windows LAN Speed Testing:
Follow the below steps to use Totusoft’s LAN Speed Test.

  1. Download and Run: First download the Speedtest from Totusoft by clicking here. Make sure to save it to a place on your hard drive where you can access it easily every time you need to run it as it does not install as an application. To run the application double click the .exe that you have just downloaded.
  2. Run a SpeedTest: Click the “Start Test” button located at the bottom right of the application window. Navigate to the network device you want to test with and choose a folder where you can temporarily write a file to. Click OK once you have the folder highlighted. The next configuration window will ask for a file size in MB so choose something around 150 if you have a 100 Mbit/second network or something around 1500 if you have a gigabit network. Once you click OK the test will start to run. Depending on how big of a file you chose the results may take a little while and when they are done they will look like the below.

    Totusoft LAN Speed Test

Linux LAN Speed Testing:

  1. Install iperf and ntop: First install ntop and iperf via yum by using the below two commands.
    Install iperf via yum syntax


    1. yum install iperf

    Install ntop via yum syntax:


    1. yum install ntop
  2. Run ntop: Now type “ntop” from the CLI of each Linux device to run through the initial configuration. You will only be asked two questions which will be the username and password for the admin user. After a couple minutes break out of the application by clicking Ctrl-C.
  3. Start ntop Daemon: Now run the below command to start ntop.

    1. /usr/bin/ntop -d -L -u ntop -P /var/ntop --skip-version-check --use-syslog=daemon

    This provide all of the correct switches to get ntop running and if successful it will run in the background as a daemon on port 3000. You can verify the port is open by using the netstat command as shown below.


    1. [root@dev ~]# netstat -an | grep 3000
    2. tcp 0 0 :::3000 :::* LISTEN
  4. View ntop Pages: Now open up the ntop HTML pages in a browser.  The URL will be your IP address on port 3000 as shown in the example below.ntop URL Example: ntop pages will look similar to the below.

    ntop Local Network Statistics Graphing

    Be sure to look around the ntop pages to see pages like the Traffic Summary page shown below.

    ntop Traffic Summary Page

  5. Start iperf Listener: Now to generate some traffic to show up in the ntop graphs we will use iperf. First we need to fire up the iperf listener. This can be done by typing the below on one of the Linux clients or servers.

    1. iperf -s
  6. Start iperf Client: Now on another Linux server or client issue the below command to start traffic generating between the two devices.

    1. iperf -c -i5 -t 300

The above methods will give you a good view of your LAN through put between devices. Use the man pages for iperf and ntop to find out more about each application. You can play around with file size, length if test, and other settings as well. The more you know about where the hiccups might be on your LAN the easier life will be on your network.