techblog

Central America and DNS errors

Jul 9, 2013 by Christoph // 1 Comment

Hey.
As some of you may know I am currently travelling in Central America. I was quite fascinated how many WiFi spots they have in restaurants, hostels, bus stations, airports and so on. But I was also surprised how many of them won’t work because of issues with the Domain Name Service (DNS).

Since a lot of travellers complained to me about this problem (after they figured out I am an IT guy <ironic>and that I am more than pleased to fix their computer issues during my trip</ironic>) and where happy about the short fix, I wanted to write this one down really quick and easy so that even non-IT people can change it by themself. So I don’t have to get involved and end up fixing computers because of viruses, IE search bars, funny background tasks and so on. 😉

So, here we go.

Situation

  1. You are connected to a WiFi router with one of your devices like a PC, Mac, iPad, someOtherPad, …
  2. You get a DNS error opening a website (sometimes major sites like google.com or facebook.com are working, but others are not)
  3. You really need to go to the internet, and you have nothing else to do in beautiful Central America (really, think again!)

Background on the Problem

As far as I experienced, it is mostly not a problem of the Hostels or Restaurants WiFi (remember, you already are connected to it) but an issue of their internet providers. Stop complaining, there wasn’t a single WiFi router there some years ago!

Simple explained:

The internet world doesn’t actually work with web addresses like ‘http://www.google.com”, but with so-called IP adresses like ‘173.194.37.0’. Since humans are better in remembering names but numbers, there are servers (computers) that are doing this domain name translation for you. So if you put an address into your Internet Explorer, Safari or some other Application, the computer checks the address against a Domain Name Service Server, who should reply with a valid IP address. This IP address is pointing to the server that is responsible for your request, like a server of Google or Facebook, and you can start communicating with it. (detailed and “more technical” description here)

What I found was, that the Domain Name resolution does not work in 80% of the places you connect to the internet. I am not sure about what exactly the problem is, but it seems the DNS servers the translation request is sent to, don’t have the address you request and therefore can’t give you a valid response. That is when you are running into an error.

Solution

There is a simple fix to it, working with Windows, Linux, Mac OS, iPads, and so on (but not on Windows Phones *arghhh*). We simply change the IP address for the DNS server that we want to use for the domain name translation. As you can imagine, there are some out there in the World Wide Web. Tim Fisher maintains a list of free public DNS servers we can use for this purpose here. For simplicity, we will use the easy to remember IP for the DNS of Google: 8.8.8.8

I will explain the steps for a Windows system only. If you use Linux, you should be able to change it by yourself since your are already a geek. Mac OS user please see this post explaining the change.

Windows:

  1. Open the File Explorer, left click on “Network” and click “Properties”
  2. “Network and Sharing Center” opens and you click “Change Adapter Settings”. Depending on your installation you are prompted for an administration password, so you are allowed to change the settings.
  3. Right-click your Wifi Adapter (usually something with “WiFi” in it) and select “Properties”
  4. Under “This connection uses the following items” select “Internet Protocol Version 4 (TCP/IP)” and click “Properties”
    u1
  5. You will see another window, usually with all settings set to “obtain XY automatically”. We will change this for the DNS to “Use the following DNS server address” and put the numer 8.8.8.8 in there, Googles DNS server:
    u2
  6. Hit “OK” and “Close” to store the settings, open up your browser and try again.
  7. Should work now. If not, try turing your computer and the router off and on again. Still not working? Find a hammock and a book!

Hope that clears things out! Let me know if you need further assistance…I will try to update this blog post so all of you understand what I am talking about! 😉

Have fun travelling, take care and don’t spend too much time on the internet … rather go for a swim, a tour, swing the hammock or read an awesome book!


1 Comment to “Central America and DNS errors”

  1. Sharad Gandhi

    Hi Christoph – Very useful and well explained. Thanks a lot. Have fun! … Sharad

    Reply

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