But Facebook is also ginormous, so in addition to its own DNS, it uses something called Border Gateway Protocol, or BGP. Remember when we talked about how DNS figures out the address of the computer you want to connect to? Well, keeping with the letter metaphor, once you write a letter, address it to your friend and drop it in a mailbox, someone has to figure out all of the logistics of actually getting that letter from one place to another. For the internet, that’s BGP. BGP figures out the best route from your computer to the computer you’re requesting a website from. Most companies do not have their own BGP computers- this is a system at the level of Internet Service Providers and ginormo tech companies. Unfortunately for Facebook, that includes them.
So, now you know what facebook’s backbone network is, what DNS is, and what BGP is.
What the heck happened?
During a routine maintenance check, an engineer accidentally took down facebook’s entire backbone network. All the computers were still on and working; they just weren’t connected anymore.
Once the backbone network was gone, Facebook’s DNS noticed that it couldn’t find any of the computers that it used to have addresses for. It cheerfully updated itself to reflect that it couldn’t find those domains and let Facebook’s BGP computers know.
Facebook’s BGP computers updated themselves to basically tell everyone requesting a facebook domain, “Sorry, you can’t get there from here.” Since there were no more paths to Facebook’s computers, you had to spend the day just telling people you like them face to face. Like a barbarian.
And now, when someone talks to you about the Facebook outage, you can whip out your new lingo, ruin a conversation and lose a friend. Hooray! Technology!
Top Image: Hassas_Arts/Pixabay