Friday, March 9, 2012

Troubleshooting Internet Problems (Part 1)

For starters we are going to do a little troubleshooting. Now, I have been taught to troubleshoot a problem, especially Internet related problems, from the bottom up; however, I like shortcuts, so rather than starting from the bottom, we are going check a few things that commonly go wrong first before starting from the bottom. These common problems usually include a single website that simply is not work at the moment, a single computer or device that is not working, or your ISP is experiencing a temporary outage.

You can find troubleshooting network internet connection problems part 2 here: http://www.computer-skills.info/2012/03/troubleshooting-internet-problems.html

And you can find part 3 on troubleshooting the computer side here: http://www.computer-skills.info/2012/03/troubleshooting-internet-problems_18.html

The very first thing to do when you encounter a website that does not work is to try some additional websites to ensure that that particular website simply is not down at the moment. When you encounter a website that does not work or your internet access is down, you will usually receive a 404 error message that Internet Explorer cannot display this page (the message will vary slightly depending on what internet browser you are using). Some websites to try when this happens are www.google.com, www.microsoft.com, www.bing.com, and www.yahoo.com.

Once you have determined that cannot access any websites on the device, the second thing to check is from a second device – if you have one anyway. If you find that your second device does not have internet then you will want to check with your ISP to see if you have an internet connection. This has a second benefit as well, if the second device has internet, then problem has to be the first computer.

The third thing to check is whether or not your ISP is up and providing you with an internet connection! This may sound stupid but I actually know someone who went and bought a brand new computer because their Internet did not work. Turns out the Internet still did not work on the new computer! A simple check or call to the ISP would have saved some money; as it turns the ISP was down for a couple days due to a lightning strike.

There are couple ways of checking whether your Internet connection is up:

  • The best way to determine if your Internet connection is up is by asking your ISP! They can usually check right from their end all the way up to modem in your house – at which point it usually becomes your problem.
  • If you have a router, enter your routers status page. For Linksys routers, you would go to http://192.168.1.1, type in the password (default is admin), go to the Status page. On the screenshot below you will noticed that under the Internet Connection status that everything has 0.0.0.0 or is blank, meaning there is no internet access (does not necessarily mean your ISP is down though!).
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  • Ping test – this is a really simple test that tests the connection by sending a ping to a server. To do a ping test go to Start and in the search box type in CMD or if you have Windows XP go to Start >> All Programs >> Accessories >> Command Prompt.
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    In the Command Prompt window type in Ping 8.8.8.8, this will Ping one of Google’s DNS servers. You can also type in Ping google.com. If you get a reply back then your Internet service is working. Also, if the Ping 8.8.8.8 works, but the Ping google.com does not work, then there is a possibility that your ISP’s DNS servers are down or something within your own network is blocking the DNS information.
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Obviously if your ISP says the connection is down between their equipment; then there is nothing else you can do except wait for them to fix the problem.

I will cover specific troubleshooting scenarios in another post. However, before I close this post, I think it is important to give a quick overview of your internet browser works.

For starters everything on the internet has an IP address, this number that identified all devices on the internet and allows one to connect to them and allows data to be routed through the world! An IP address is made up of 4 sets of numbers, for example 192.168.1.138 or 10.2.255.128. This works great for computers that read numbers, but for us humans, remembering these numbers does not work so well, imagine you want to go to Google, instead of typing in http://www.google.com you have to type in http://74.125.225.40?

For this reason DNS was invented, which allows devices to also have a name associated with that IP address. So instead of having to type in an IP address you can type in www.google.com! For the internet browser though this means that it first needs to convert that name into a number, since that name means nothing to the computer.

This is where your ISP comes in and provides you not only with an IP address to get online with, but also DNS servers, which take the name (google.com) and send Google’s IP address back to your computer’s web browser. So when you go to www.google.com, the first thing that happens is the request gets sent to your ISP’s DNS severs, the DNS servers then send back to your browser the IP address of www.google.com (74.125.225.40); the web browser then attempts to access 74.125.225.40.  Incidentally, this can actually happen a couple times since a particular website may have to pull data from more than one location.

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