On Monday evening, the social network and its associated services – Instagram, WhatsApp and Messenger – abruptly disappeared from the Internet’s road map equivalent.
By Martin Untersinger and Olivier Clairouin
How could a juggernaut like Facebook, whose services are used by almost half of the planet, “disappear from the Internet” so suddenly, Monday, October 4?
It is indeed a disappearance: shortly before 6 p.m., the paths leading to Facebook’s servers were purely and simply erased from the equivalent of the Michelin map on the Web. No Internet user in the world could access Facebook or all the services using its infrastructure, primarily Instagram, WhatsApp and Messenger, all of which belong to the Silicon Valley giant.
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• What is BGP, the Internet “road map”?
To understand, you have to look at a protocol that is as little known as it is necessary for the functioning of the Internet: the Border Gateway Protocol, or BGP. It is, all things considered, the equivalent of a large collaborative road map or an Internet GPS: it allows you to determine at any time the best way to go from point A (your smartphone or your computer, for example) to point B (here, Facebook).
This is explained by the very nature of the Internet, made up of millions of servers and networks (access providers, like Orange, major social networks, like Facebook, content providers, like Netflix, etc.) connected to each other and forming a gigantic labyrinth. To guide Internet users, all these players share a large collaborative map, which they are responsible for constantly updating, to allow data to make its way through the big web.
• Why do we also hear about “DNS”?
The first error messages suggested that there was a problem with the domain name systems (“Domain Name Systems” or DNS). The role of DNS is to translate a domain name made up of letters (for example, “www.facebook.com”) into an IP (Internet Protocol) address, that is to say the technical and unique identifier. a server on the network (for example, “216.239.32.107”) in order to make it understandable by a machine. This is what allows you to connect to your favorite site, www.lemonde.fr at random, without having to memorize the painful series of numbers corresponding to its address. A bit like a directory allows you, with the name of a person, to find his postal address in order to visit him.
It is only once equipped with this IP address that the smartphone or the computer which tries to connect to a site is able, with the BGP, to find the corresponding server and to display the contents (a messaging , a social network, a video…). As Cloudflare, an Internet infrastructure company, summarizes, DNS tells you where to go, and BGP tells you how.
DNS tells you where to go, and BGP tells you how
Except that in order to be able to use DNS, you must, as with any type of server, also know how to get there. However, without BGP, finding one’s way was precisely impossible. To use the metaphor of the directory, it is a bit as if the directory is not at your house but at a friend’s house. Without BGP, it was already impossible to use the information provided by the directory, but it was also quite simply impossible to even go and look for it.
• What triggered the outage in the first place?
We do not know yet. The chain of events is not yet fully known at this stage, but shortly before 6 p.m. on Monday, Facebook made a BGP update (the “collaborative map”, therefore) by explaining that certain paths leading to its DNS were no longer valid. It was suddenly very difficult to reach these servers, which blocked much of the connections. Facebook has also, more broadly, declared as unusable all the computer paths leading to its servers, effectively cutting itself off from the rest of the Internet.
As is often the case with problems involving DNS and BGP technologies, the origin of the error is most likely human. As evidenced by a first blog post published Monday evening, Facebook remains very discreet at this time on the precise details that led to this unprecedented outage. On his page, Mark Zuckerberg said to himself ” sorry “ of this interruption.
Still, the effects of this outage on Facebook services were felt throughout the network. Various tracking services immediately noticed a collapse in Internet traffic handled by Facebook.
And several experts have also noticed more general Internet slowdowns – not necessarily visible to Internet users. The fault of hundreds of millions of devices constantly asking for the location of Facebook’s servers, a location that had disappeared from maps.
By Gazette Haiti with Le Monde
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