Learning About Internet Traceroute

If you have ever wondered how data gets from a website to your Mac, you can use Traceroute to see the full path data takes through the Internet. You may be surprised by how many hops it takes to load a webpage. Viewing a few trace routes will help give you an appreciation for how complex the Internet we take for granted can be.
Video Transcript / Captions
Closed captioning for this video is available on YouTube: Learning About Internet Traceroute.

Have you ever wondered how information gets from a website somewhere to your computer. It's not a direct connection. When you're looking at a website you're not connected directly to that website. Instead you're connected to your ISP. Probably a local hub at your ISP. Then maybe a national hub at your ISP or a regional hub. Then you go through several different servers until you finally get to the network that the website is on and then maybe several different network routers until you get to the actual server that has that website. It's a long path between your computer and a website and you can view that path using something called Traceroute.

So there are two ways you can use Traceroute on your Mac. The first way I'm going to show you is to use the Terminal app. So I'm going to use Spotlight, Command space to bring up Spotlight search, type Terminal, hit Return and it launches Terminal. Now to run Traceroute I just type traceroute, one word, and then the website I want to trace the route to.

So, for instance, let's just try MacMost.com and hit Return.
It's going to start tracing the route from my local network out to the internet, through different hops all the way to macmost.com. You can see here it takes fourteen different hops to get from my computer to macmost.com. Everytime I'm loading a piece of the website, every little image, every bit there, it's coming through all of these different hubs, these different hops here, and through different services going through the country as it gets from my server to my computer.

Another way you can access Traceroute is to run an app called Network Utility. You can do the same thing here. Spotlight and start typing Network Utility and it comes up. Network Utility has all these different utilities at the top. You select Traceroute and then you type the website you want to try to trace to. Then you trace and you get basically the same information here.

This interface actually makes it a little bit easier to do. You don't have to go into Terminal. You can try all sorts of different sites and it will start tracing its way to there.

Now if you ever see, in a Traceroute, these little asterisks here that just means there's a delay in the trace. So the more complex the route the more chance you're going to have those. They're perfectly normal. Notice also it takes a lot longer sometimes to do a traceroute than it actually does to load the webpage. That's because it's gathering all sorts of information about each hop there. How long it takes. Maybe grabbing an actual name for the server rather than just the actual set of numbers that make up the IP address.

So this gives you some useful information and it's a good reminder to everybody that the internet is a complex thing and it takes many steps to perform all the different actions that we just take for granted on the internet. So it's useful and educational to use Traceroute every once in a while to see how the internet works.