DNS Benchmark and how to run one

In order to find out what your actual DNS lookup speed is, we will be running a DNS benchmark. By doing so, we will have a pretty good idea of how far we are from various DNS servers nearby and from around the world.

Also, if you’ve installed a personal DNS server on your LAN previously, you will have a pretty good idea whether it is working and caching entries properly or not. In order for us to do the benchmark, we will be needing a Windows-based computer to run our software.

DNS Benchmark Software

We will be using the DNS benchmark software by GRC. This one in particular allows us to conduct an analysis of our DNS servers, how they behave, and whether any particular issues may arise such as potential security holes.

Connection stability

Please be aware that in order for this benchmark to produce the most accurate results, you will need to make sure your connection is stable and no downloads are running in the background or on any computers within your LAN.

You can get the software from here. You won’t be installing this one, as it is just a single-executable file. Feel free to place it in any folder you like or keep it in the “Downloads” folder.

Open up the DNS Benchmark by clicking on “DNSBench.exe”.

You are given an introduction. Read through it a bit to understand what this software
is and some tips needed to get started. If this is your first time running it, wait a bit for DNS server data to be gathered and initiated for testing.

Click on the “Nameservers” tab.

You will now see a list of DNS servers the benchmark software has stored. These DNS servers will be tested all at once. If you have a local DNS server running on your network, it will appear at the top if configured correctly. If you don’t see it at all on the list, then something may be wrong with your DNS server configuration/router.

Click on “Run Benchmark” to begin your DNS benchmark.

If you click on a DNS server entry and hold down your mouse button, it will display the DNS query speed for “Cache”(red), “Uncached”(green), and “DotCom”(blue). All of these are being measured in “ms”, for example 0.047 is 47ms. This may take awhile depending on your local and overall internet connection speed. Once you’re done, the DNS benchmark will stop.

Click on the “Tabular Data” tab.

You will now see the results of your DNS benchmark. The “Min”, “Avg”, “Max”, and deviation latency of your test for each DNS server entry, as well as the reliability percentage. Anything below 100% may indicate potential stability problems, or just a simple hiccup with your internet connection which is normal. To ensure the utmost accuracy of the test, feel free to run the DNS benchmark once more.

Once you’re done looking through the results. Click on the “Conclusions” tab.

Under this tab, you will be given several conclusions and recommendations as to what you should do in order to optimize your testing experience. You will also receive suggestions on how to improve your DNS server and fix any issues that you may have. Consider taking the time reading them, and understanding how it is interpreted.

The first result that says “Only the built-in default resolvers were benchmarked.” is normal and suggests you build yourself a list of DNS servers for optimization.