Earlier this week, we started getting reports from several of our users that they couldn't connect to our website anymore. This was very strange because 1.) we hadn't changed anything and, 2.) clearly most of our users could connect just fine.
After some investigation, we noticed that the people that were having connection problems all used "shaw.ca" as their ISP. Some more testing revealed that for some unknown reason, the DNS servers at shaw.ca were missing our DNS record.
(Background: A "DNS Server" is a computer that converts an Internet name like "www.stockcharts.com" into a series of numbers like "126.96.36.199" that your computer can then use to actually connect to our website. If the DNS server loses our numbers, your computer cannot find us.)
Now typically most people use whatever DNS server their ISP tells them to use. You might remember typing some numbers into a dialog box labelled "DNS Server" back when you first set up your Internet connection. Unfortunately, many ISP's are not diligent in maintaining their DNS servers. This can lead to all kinds of problems such as slow Internet times and, in the case of shaw.ca this week, missing websites.
Fortunately, there is a MUCH better way.
OpenDNS.com is a free service that provides a set of rock solid, super-fast DNS servers to anyone who wants to use them. To use the OpenDNS servers, all you need to do is replace your ISP's DNS addresses with the OpenDNS addresses. Complete instructions can be found by watching the "OpenDNS Basic" video on this page:
Using OpenDNS.com has the additional advantage of protecting you from accidentally visiting dangerous websites. It will warn you when you try to open a site that other users have flagged as dangerous.
We have used OpenDNS here at our offices for two years now and I have used it at my house for just as long. I _strongly_ recommend them to anyone that uses the Internet - especially the good people who use "shaw.ca."
P.S. Several of the shaw.ca people changed their DNS settings to use the OpenDNS servers and their connection problems went away instantly.