How to Test (specific) DNS Abilities/Hinderances

  • SpinRite v6.1 Release #3
    The 3rd release of SpinRite v6.1 is published and may be obtained by all SpinRite v6.0 owners at the SpinRite v6.1 Pre-Release page. (SpinRite will shortly be officially updated to v6.1 so this page will be renamed.) The primary new feature, and the reason for this release, was the discovery of memory problems in some systems that were affecting SpinRite's operation. So SpinRite now incorporates a built-in test of the system's memory. For the full story, please see this page in the "Pre-Release Announcements & Feedback" forum.
  • Be sure to checkout “Tips & Tricks”
    Dear Guest Visitor → Once you register and log-in please checkout the “Tips & Tricks” page for some very handy tips!

  • BootAble – FreeDOS boot testing freeware

    To obtain direct, low-level access to a system's mass storage drives, SpinRite runs under a GRC-customized version of FreeDOS which has been modified to add compatibility with all file systems. In order to run SpinRite it must first be possible to boot FreeDOS.

    GRC's “BootAble” freeware allows anyone to easily create BIOS-bootable media in order to workout and confirm the details of getting a machine to boot FreeDOS through a BIOS. Once the means of doing that has been determined, the media created by SpinRite can be booted and run in the same way.

    The participants here, who have taken the time to share their knowledge and experience, their successes and some frustrations with booting their computers into FreeDOS, have created a valuable knowledgebase which will benefit everyone who follows.

    You may click on the image to the right to obtain your own copy of BootAble. Then use the knowledge and experience documented here to boot your computer(s) into FreeDOS. And please do not hesitate to ask questions – nowhere else can better answers be found.

    (You may permanently close this reminder with the 'X' in the upper right.)


Active member
Sep 29, 2020
Excuse me Please:

I am well aware of Mr. Gibson's DNS Benchmark tool which I use quite frequently of late.
Speed of resolution is great; However, now that security is of greater import, and singular DNS providers that have more security being preferential, while most carriers view their clients as Vultures whom view their kill just prior to swooping down, I am seeking something more specific in terms of testing DNS.
*I am on a WISP connection (formerly Sprint, presently on tmobile that bought Sprint some months back)
*i noted in times past ShieldsUP! would identify me as ...sprintsoandso...
*currently ShieldsUP! identifies me as
*note also, that Arstechnica posted a reminder about "tmobile gives arbitrary date to optout before they start selling your data"
{which noting, i was unable to find on any of my Sprint account pages a means to optout}

Further, I note some people using NextDNS are experiencing DNS Resolution/browsing problems with specific errors as quoted below.
This network is blocking encrypted DNS traffic.
The names of websites and other servers your devices accesses on this network may be monitored and recorded by other devices on this network.
Which they stated once they switched off NextDNS/encryption, their browsing was uninterrupted.
(showing OBVIOUSLY their carrier is purposefully collecting data, and actively preventing security.)

Also, over the last, oh, maybe month of so, I have been noting a weird inability to browse the Internet.
Now it need be stressed that NOTHING has changed on my system over last 6mo. or so (probably longer)

Be there a tool that can Test & IDENTIFY one's connection for abilities/hindrances/annoyances/et al using DoH or other secure means of resolving/browsing?
Last edited:
First, knowing which DNS servers your operating system and web browser are using can be hard. To that end, I have a list of tester web pages here

There is also a cheat sheet for nslookup for Windows users to see which DNS servers their OS is using outside of the browsers.

Now that we have encrypted DNS support in most every desktop browser, I suggest you try it out. You can have each browser configured with a different encrypted DNS provider. And, don't forget to try a VPN, as that changes everything about DNS too.