Someone reposted Trey Harris’ famous story about the 500 mile email. The TL;DR is that Harris, working as a university system administrator, received a call from the Statistics Department claiming that they couldn’t send an email further than about 500 miles. If you know anything at all about how email works, your reaction would be the same as Harris’: Yeah right.
Oddly, though, it turned out to be true. It was the Statistics Department, after all, and they had all sorts of data supporting the claim. Harris ran his own tests and discovered to his astonishment that it was true. Email to a site closer than 500 miles worked fine. Those to sites further away than a little over 500 miles invariably failed.
I’ve written about this at least a couple of times before but it’s such a good story that it’s worth repeating now and then for people who haven’t heard it. The solution makes perfect sense once you know what it is but until you do it’s seems like an impossibility.
Take a look at Harris’ original post for the answer and for the amusing story. You may even learn a new way of thinking about network problems. Sometimes you need to look under the layer where the problems seems to exist to discover what’s actually going on.