Monitoring Internet Reachability in Real-Time

Martin Brinkmann
May 15, 2008
Updated • Jul 15, 2014

What's the first thing you do when your Internet connection is not working? I changed my reasoning from thinking that it was related to my computer to one that assumed the Internet Service Provider was responsible for the outage.

Well that's not 100% true but I know several signs that tell me if it is my fault or the fault of my ISP.

I usually restart my router to be on the safe side but that's it. Sometimes you can make a connection to the Internet but that connection feels slow, you get disconnected regularly and websites may not be loading properly.

One way to find out if the problem is located on your side is to perform a tracert command to the target server. If that tracert times out you pretty much know the IP address of the server responsible for that along with information about the country the server is in. That is, unless the first hops time out already.

This is also the basic approach of Hubble, a service that monitors Internet reach-ability in real-time. Instead of using one tracert at a time they send out more than 100k every 15 minutes to monitor reach-ability problems throughout the world using a Google Maps mashup to provide a map of so called black holes, meaning servers that are unresponsive or have a reduced reach-ability.

The interesting information for the users are the IP addresses or ranges of those servers and the country column of the table. Sorting the column by country reveals problematic server at a glance which can help determining if the problem is located at your end.

Update: Hubble appears to be no longer available as a service that you can browse. The research behind the service on the other hand is still accessible on the Washington University website.

Update 2: The search is no longer available as well. You can however still read about it on the website to find out what it was all about.


Tutorials & Tips

Previous Post: «
Next Post: «


  1. GRTerrero said on May 17, 2008 at 10:34 pm


    My grandmother used to say “Don’t play with your ping or you’ll go blind.”

    Sorry…slow Saturday so I have to amuse myself.

  2. Tobey said on May 16, 2008 at 7:20 pm

    Very interesting, thanks for sharing.

  3. Cheryl said on May 15, 2008 at 4:22 pm

    I usually do the ping test. I ping my IP and the IP of my ISP to see which one’s not working.

  4. Angelo R. said on May 15, 2008 at 3:09 pm

    This is a great website, but I think the easiest thing still remains the trace route command. Coupled with ping and ipconfig /all you can pretty much get the gist of any problem you’re having with your internet connectivity.

  5. yash said on May 15, 2008 at 1:56 pm

    typo: whats the first missed thing

Leave a Reply

Check the box to consent to your data being stored in line with the guidelines set out in our privacy policy

We love comments and welcome thoughtful and civilized discussion. Rudeness and personal attacks will not be tolerated. Please stay on-topic.
Please note that your comment may not appear immediately after you post it.