Facebook’s Day Off | Why Facebook Went Down.

Jay Dwayne
5 min readOct 12, 2021


Many of us have had our own fair share of Peer pressure and I, like most people couldn’t take the weight of the question from my ‘friends’ asking why I am not on Facebook. Saturday the 17th of September 2011 was that day where I got to do that thing and I officially joined the Social Network to fit-in the cool kids niche. Having been on Facebook for exactly 3,670 days, never have I ever imagined that a Tech Giant like Facebook would ever go offline but maybe you did. Did you ?

On the 4th of October, 2021, Billions of users were unable to access Facebook, Instagram and WhatsApp for hours while the social media giant scrambled to restore services. ( Facebook acquired Instagram in 2012 for $1Billion and also acquired Whatsapp in 2014 )

The mass outage on Monday was triggered by an engineer command that inadvertently disconnected its services and knocked them offline The social network Facebook and its subsidiaries, Messenger, Instagram, WhatsApp, Mapillary, and Oculus, became globally unavailable for a period of six to seven hours. The outage also prevented anyone trying to use “Log in with Facebook” from accessing third-party sites.

Facebook’s mass outage that pushed its major services offline was caused by an engineer error made during routine maintenance of its network of data centres. Santosh Janardhan, Facebook’s vice-president of engineering explained that Facebook’s outage was triggered by a command that was issued to assess the availability of the company’s global backbone capacity — the network it has built to link all its computing facilities together.

During the outage, many users flocked to Twitter, Discord, Signal, and Telegram, resulting in disruptions on these apps’ servers. The outage was caused by the loss of IP routes to the Facebook Domain Name System (DNS) servers, which were all self-hosted at the time. Border Gateway Protocol (BGP) routing was restored for the affected prefixes at about 21:50, and DNS services began to be available again at 22:05 UTC, with application-layer services gradually restored to Facebook, Instagram, and WhatsApp over the following hour, with service generally restored for users by 22:50

Why did Facebook go down?

Just before 5pm UTC, people began noticing they could not access Facebook, Instagram, WhatsApp or Messenger. It would be more than five hours before services would begin to be restored.

Facebook issued a statement on Tuesday confirming that the cause of the outage was a configuration change to the backbone routers that coordinate network traffic between the company’s data centres, which had a cascading effect, bringing all Facebook services to a halt. It meant not only was Facebook gone, but everything Facebook runs disappeared too.

Others have provided a bit more detail on why Facebook vanished from the internet.

Cloudflare — which had its own recent internet outage issues — has provided a detailed explanation about what happened. It involves two things that sort out how the internet is the internet — that is Domain Name System (DNS) and Border Gateway Protocol (BGP).

BGP (Border Gateway Protocol) is the protocol underlying the global routing system of the internet. It manages how packets get routed from network to network through the exchange of routing and reachability information among edge routers. BGP directs packets between autonomous systems (AS), which are networks managed by a single enterprise or service provider.

BGP creates network stability by guaranteeing routers can adapt to route failures: when one path goes down, a new path is quickly found. BGP makes routing decisions based on paths, defined by rules or network policies set by network administrators.

BGP — Using The Route Maps For Bgp Filtering Interxion

The internet is a lot of connected networks. A lot. So that means to keep order of things, you need something like BGP to tell you where you need to go.

DNS is essentially the address system for the location of each website — its IP address — while BGP is the roadmap that finds the most efficient way to get to that IP address.

Cloudflare said Facebook essentially told BGP through a series of updates that those paths to Facebook no longer existed.

But not just for Facebook, everything Facebook runs.

That meant people trying to reach Facebook couldn’t find the path to access it. Why were Instagram, Messenger and WhatsApp down?

All of Facebook’s services were affected, not just Facebook. It included Facebook’s own internal systems, with reports staff were locked out of offices, and could not access their own internal communications platform.

Why did it take so long to fix?

Facebook’s own internal systems are run from the same place so it was hard for employees to diagnose and resolve the problem. Facebook runs EVERYTHING through Facebook, so the usual way you would fix a problem like this was also not working. Facebook staff were reportedly unable to access their own communications platform, Workplace, and were unable to access their office due to the security pass system being caught up in the outage. Facebook indicated the duration and severity of the outage meant the systems were being brought back to full capacity slowly.

Facebook have also been hit hard by Whistleblower Frances Haugen, a 37-year-old data Scientist for Facebook who left in March this year. Haugen has leaked multiple documents and conversations to the Wall Street Journal such as the X Check whitelist system Facebook have for “VIP” users, and more recently they leaked internal research results that Instagram had conducted; the research showed that the company are aware of the effect their app has on teenage girls. One harrowing quote from the internal slides that were leaked is as follows, “We make body image issues worse for one in three teen girls,” You can read more about the leak without a subscription here: Facebook knew Instagram made teenage girls feel worse about themselves.

Frances Haugen appeared and testified before a Senate subcommittee on Tuesday to speak further about the allegations she made to the US Securities and Exchange Commission regarding Facebook’s bad practice, especially around the 2020 election and the above leak regarding Instagram’s effect on teenagers.

Facebook harms children and weakens democracy: ex-employee. Frances Haugen added.



Jay Dwayne

As a software engineer, designer, graphic artist, guitarist, and martial artist, Jay brings a unique blend of skills and passions to every project he undertakes