- Docker logs tail: Troubleshoot Docker containers with real-time logging - Wed, Sep 13 2023
- dsregcmd: Troubleshoot and manage Azure Active Directory (Microsoft Entra ID) joined devices - Thu, Aug 31 2023
- Ten sed command examples - Wed, Aug 23 2023
In this article, we will have a look at the following free tools:
- CommTest
- iPerf
- Network Speed Test
- Speedtest.net
- Fast.com
CommTest
CommTest is a program used to test network connectivity performance and transfer speeds between two computers. It measures the transfer speed, latency, and packet loss between the two computers.
To use CommTest, you install it on both computers and then use the Connect button to configure the test's target. Unfortunately, the utility is getting very long in the tooth and only shows compatibility with Windows 8 as the highest Windows OS on the site. However, I found that I was able to install it on both Windows 10 and Windows 11.
The installation is a "next, next, finish" process. Once CommTest is available on both computers, start it using the Connect button.
Launching the connect functionality with CommTest
Next, enter the destination IP address of your CommTest host.
Specify the target of the network speed test with CommTest
CommTest begins operations immediately after the destination IP address is provided.
Running the network connectivity test with CommTest
You can download the CommTest utility directly from Roadkil.net.
iPerf
The final tool on the shortlist, called iPerf, is well known among network professionals. You can use it to test speeds between two hosts on a LAN, across the Internet, etc. It is similar to what you can do with CommTest. It allows you to take active measurements of the maximum achievable bandwidth on IP networks. However, it provides a much more customizable and configurable testing tool.
The iPerf utility is feature rich with command line parameters that allow you to create highly customized network speed tests between hosts. You can tune and tweak parameters around timing, buffers, and protocol settings for TCP, UDP, and SCTP.
First, extract the downloaded iPerf ZIP file, which you can download here. Once extracted, note the wide range of options available for iPerf.
iPerf command line options and parameters
For a basic test, we need to run one host as an iPerf server and one as an iPerf client. The basic command for the iPerf server is:
iperf3.exe -s
iPerf server from the command line
Once you have the iPerf server running, you will need to run iPerf on the designated iPerf client. The syntax for an iPerf client is:
Iperf3.exe -c <IP of your iPerf server>
iPerf client connecting to the iPerf server
Find our comprehensive review of iPerf here.
Network Speed Test
Network Speed Test is the highest-rated app you will find when searching "network speed test" in the Microsoft Store. Installing the app is as easy as clicking the "Get" button.
Network Speed Test app in the Microsoft Store
When you run the app, it displays detailed information regarding your connection speed, including:
- Connection type
- Internet status
- Host name
- Delay
- Download
- Upload
Viewing the network speed test results after running a test
You can take a look at Network Speed Test here.
Speedtest.net
Speedtest.net can't check your LAN between computers, but testing your Internet connection can uncover problems with your download or upload speeds, latency, jitter, etc. In addition to visiting the Internet site, Speedtest.net has mobile apps available for iOS and Android, as well as a Windows Store app.
Visiting speedtest.net to run an Internet speed test
Check out speedtest.net here.
Fast.com
Another simple way to determine whether you are getting the speed you have paid for is to visit fast.com. It is a site owned by Netflix that gives you a quick, easy test of your Internet speed without additional details.
Fast.com by Netflix provides a quick easy Internet speed test
Fast.com by Netflix provides a quick, easy Internet speed test
Visit fast.com here.
Wrapping up
Performing Internet speed tests and simple network speed tests between two hosts on the local area network can help uncover network performance, latency, connectivity, and other problems.
Subscribe to 4sysops newsletter!
The tools listed can help quickly measure network speed, without complicated setup time, to find performance issues. In addition, all of the tools listed are free to download and use.
Nice article.
1) When working on network servers, I tend not add any tools unless required. My favorite in windows was pathping where I was able to assess packet loss and latency in the different hops in the connectivity test. In one used case, it helped us identify packet loss in a BGP route that was affecting a VPN to a data center. With the path ping data we were able to convince the ISP to adopt a different route.
2) When troubleshooting network congestion, I normally create test VM / host with iperf to simulate the server-client traversing a switch or firewall.
3) Thanks for the tip about fast.com. It seems like with the settings button there one can configure it to use multiple servers.
Well said @ratan. Pathping is an excellent built-in tool to check latency and packet loss. I also avoid using 3rd party tools/services particularly on servers.
In an effort to save everyone frustration, never use iperf3 on Windows server.
Can you please elaborate?
The TCP stack implementations are different between Windows and Linux. This is why network engineers prefer Linux hosts when using iperf3.
Most iperf3 Windows binaries use an old/buggy cygwin1.dll that limits the window size, see https://techcommunity.microsoft.com/t5/networking-blog/windows-network-performance-suffering-from-bad-buffering/ba-p/339668. It’s not so much that you can’t use Windows, but Windows requires several optimization tweaks to get the most out of your line speed, see https://fasterdata.es.net/host-tuning/ms-windows/.
why?
See my reply above.
Thanks Bo for the info about Cygwin- I never realized that as I always used linux too. Thanks for the reference too. Now there you go- if we are using the tool from Cygwin (unix-like) why not use a dedicated linux host.
In my experience, adding troubleshooting-tools to a production server (may be a bit our of scope. for our discussion) should be a last resort. The problem is that if you are using a buggy piece of software or forgot one that has acquired a vulnerability, you expose the production server to security risks. The only one I ever used was a portable wireshark and winpcap to troubleshoot LDAP authentication issues and to analyze packets that uses older protocols such as SMB1. But I remove them once the troubleshooting is done.
But why do some speed test shows different measures and it’s not a small difference almost 20 to 30 mb/s sometimes more?
When investigating network issues, I’m particular about the tools I add to a server. A favourite in Windows is Pathping, which can be used to measure packet loss and latency over different hops. In one case, it was used to identify packet loss in a BGP route that was impacting a data centre’s VPN. With the data from Pathping, I could prove to the ISP that a different route should be taken.
To troubleshoot congestions, I typically configure a test VM or host with iperf to mimic a server-to-client setup across a switch or firewall.
Additionally, I recently learnt about Fast.com, which offers a great deal of flexibility with its settings button; allowing users to connect to multiple servers at once via the click of a mouse.