What Is DNS Recursion And Why Should I care?

Hello and welcome to an occasional post from me, as a direct result of my working life, and some tech tips I come up with now and again to fix things.

DNS recursion is one of those things I came across when moving my web site from an in-house server to a cloud-based much faster server at Vultr, whom I highly recommend if you want a dedicated virtual private server.

I use a Windows-based DNS (Domain Name System) server called Simple DNS. I have used it for years, but only in-house.

When I moved, I got a new IP address for my cloud-based server, as you would. I then found that oddly, some devices, Emma’s Galaxy S5 was one, would not load any web sites, instead giving an error, something to the effect of bad domain config, or DNS Probe Failed, or other such errors.

I was racking my little brain for a couple of weeks over this. I had written to JH Software, the developers of SimpleDNS for support and they had made a couple of suggestions, which didn’t fix the problem. What was odd though is that newer devices like my Nexus 6P and Angie’s iPhone were going on the web with no problem, but maybe a bit slow.

It seemed that telling my router to use Google’s open DNS servers, which do allow recursion, 8.8.8.8 and 8.8.4.4 would work, even for the Galaxy S5, but when I pointed to my own IP address as the primary DNS server from my router, then the S5 couldn’t get out when connected to our wi-fi.

Eventually, I got it. It was DNS recursion. As a security measure, recursion should be disabled on your own DNS server, other than for clients from your own IP address. If recursion is not available to you, then you won’t reach many web sites.

For an explanation of DNS Recursion, please read this article I found here:-

SimpleDNS Recursion

The solution was to go into Tools, Options in SimpleDNS go down to the option called Recursion in the DNS branch and enable recursion from non-local IP addresses, but only for trusted IP’s then add your ISP’s public IP address allocated to you.

I hope this helps some network server admins scratching their heads if they run a DNS server and wondering why they can’t get out on all devices.

Introducing Truecall VI – More Than A Nuisance Call Blocking System!

Various aspects of using a telephone are challenging for visually impaired people – in particular the interface of a modern cordless phone is via a screen, so is inaccessible.

trueCall Vi was designed specifically for visually impaired people with a number of key features:-

  • trueCall Vi’s interface is via voice menus rather than a screen
  • When you play back messages, the control is via the familiar telephone keypad rather than an arbitrary array of buttons.
  • trueCall announces callers through its speaker so you know who is calling before you answer the phone.
  • When trueCall announces a caller it can announce them by name rather than just reading out a string of digits (as is the case with existing ‘talking Caller-ID’ systems).
  • trueCall’s nuisance call management features mean that you are not disturbed by the majority of nuisance callers.
  • trueCall Vi has audible alerts telling you how many messages you have waiting.
  • trueCall Vi comes with a large print and audio manual and the serial number in Braille on the base of the unit.
  • trueCall Vi’s optional call recording feature allows you to playback your calls at your leisure. This means that if you are making complex arrangements – travel arrangements; negotiating a mobile phone tariff; etc – you don’t have to worry about taking down notes during the call.

Steve Nutt of Computer Room Services who is blind and who helped to specify and design trueCall Vi said

“Modern landline phones are challenging for blind people – they give out key information like caller-ID visually, are controlled via visual menus, and an arbitrary array of buttons on the base station and handset. trueCall Vi solves this problem by allowing your phone to be controlled through voice menus and prompts. It offers a call recording facility and the most advanced Talking Caller-ID feature available anywhere in the world. All this, and it also blocks nuisance phone calls!”

To purchase Truecall VI, simply visit this link:-

Buy Now!

Event: Sight Village 2014, Birmingham, UK – 15 to 16 July 2014

Come visit us at Sight Village 2014 at Birmingham, UK

Venue Location


  • Date: 15th July 2014 to 16th July 2014

  • Time: 10:00 to 16:00

Venue: New Bingley Hall, 1 Hockley Circus, Birmingham, B18 5BE, United Kingdom.

The exhibition is open at the following times:


15th July 2014 – 10:00 AM to 4:30 PM

16th July 2014 – 10:00 AM to 4:00 PM

Teaser

Come see our new products, such as a reasonably priced talking MP3 player, an excellent little Bluetooth speaker and Truecall VI, the ultimate tool for managing nuisance calls, with enhanced Caller ID plus our usual wide range of products and services.

The Bluetooth Speaker, known as the BlueTiger, can already be purchased here:-

Purchase a BlueTiger Speaker right now

Also come see our Boxwave keyboards for Android phones, iPhones, iPads and many other devices. You can find them here:

Boxwave Bluetooth Keyboards

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