Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2021/10/facebook-is-down.html
Facebook — along with Instagram and WhatsApp — went down globally today. Basically, someone deleted their BGP records, which made their DNS fall apart.
…at approximately 11:39 a.m. ET today (15:39 UTC), someone at Facebook caused an update to be made to the company’s Border Gateway Protocol (BGP) records. BGP is a mechanism by which Internet service providers of the world share information about which providers are responsible for routing Internet traffic to which specific groups of Internet addresses.
In simpler terms, sometime this morning Facebook took away the map telling the world’s computers how to find its various online properties. As a result, when one types Facebook.com into a web browser, the browser has no idea where to find Facebook.com, and so returns an error page.
In addition to stranding billions of users, the Facebook outage also has stranded its employees from communicating with one another using their internal Facebook tools. That’s because Facebook’s email and tools are all managed in house and via the same domains that are now stranded.
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What I heard is that none of the employee keycards work, since they have to ping a now-unreachable server. So people can’t get into buildings and offices.
And every third-party site that relies on “log in with Facebook” is stuck as well.
The fix won’t be quick:
As a former network admin who worked on the internet at this level, I anticipate Facebook will be down for hours more. I suspect it will end up being Facebook’s longest and most severe failure to date before it’s fixed.
We all know the security risks of monocultures.
EDITED TO ADD (10/6): Good explanation of what happened. Shorter from Jonathan Zittrain: “Facebook basically locked its keys in the car.”