How the Internet (Sorta) Works

Why Facebook, Instagram and WhatsApp Had A Bad Day:

How The Internet (Sorta) Works

On October 4th, at around 2:45 AM, Facebook, Instagram and WhatsApp stopped working. People couldn’t view their feeds, messages on these platforms wouldn’t send and login attempts kept failing. So, what exactly happened?

However, your device doesn’t use Google Maps- it

uses something called Border Gateway Protocol BGP)( . This is a nifty protocol that uses a lot of complex maths to determine the fastest route between your device and your destination server. All your device has

The Internet’s Phonebook In short, Facebook “fell off the map of the internet” . To understand this, we first must look at the concept of Domain Name System (DNS). All ‘Facebook’ (and Instagram and WhatsApp) really is, is just a lot of servers that process data, like your posts. To get this data your device has to be able to connect to Facebook’s servers to transfer said data. To connect to a server, your device has to know ‘where’ it is on the internet and this is why we have something called an Internet Protocol Address (IP Address). If you imagine that the internet is one giant city, with lots of buildings and roads, then you can imagine an IP Address to be like a building’s address. With this analogy, we can then say that if you want to send something to your friend, you open your phonebook (or contact list, this is the 21st century) to find their address. Once you have the address, you can easily send a letter to your friend.

In reality, DNS is a phonebookof the servers (Facebook.com)

it stores all the names with their IP Address 129.134.30.12)( so that if you want to connect to a specific server, it can ‘search up’ that server’s name and then give you the IP Address. With this IP Address, your device can then connect to the server and begin transferring data… Or can it?

The Internet’s Map Let’s go back to our city analogy. You’ve stamped a letter with your friend’s address and put it in the postbox. Now it s’ in the postman’s bag… But even if he has the address, how can he get to the address without knowing where it is? The postman needs to use his GPS, which calculates the fastest route from the post office to your friend’s address and then he is able to post your letter. to do is give the IP Address of where it wants to connect and then you’re set. If everything’s working fine, that means your “letter” (called a ‘packet’ in computer science-talk) is on its way. Once you have a steady stream of packets between your device and your target server, you have successfully connected. How Does This Relate to Facebook? According to the official announcement by Facebook, they were performing routine maintenance when, by human error or otherwise, all their connections to their backbone network think of it as their central network( ) went dark. From there, it was a domino effect as Facebook was effectively disconnected from its data centers. One of Facebook’s failsafes is that if their DNS servers can no longer communicate with their data centers, they stop giving their address to the BGP. Since it was the backbone that was affected, all the DNS servers decided that they were ‘unhealthy’ and so stopped giving their addresses. This is what caused Facebook to become ‘unreachable’ as it was essentially ‘deleted’ off the “Map of the Internet” , so to speak. As far as the internet was concerned, for six hours, Facebook ceased to exist. This is a gross oversimplification of how the internet works and why Facebook went down but it’s better than “someone pressed the wrong button” . If you’re interested in a more in-depth analysis, Computerphile (run by some lecturers at the University of Nottingham) has an excellent video here.