Facebook outage of October 4, 2021

On October 4, 2021, around 15:40 UTC, Facebook, Instagram, WhatsApp and Messenger vanished from the internet for about six hours. The explanation the group's engineering team published the next day fits in a few lines. A command run during routine maintenance, to assess backbone capacity, disconnected all the data centers from one another; the audit tool that should have stopped it had a bug. The group's DNS servers, unable to reach the data centers, withdrew their own BGP announcements. The rest of the internet no longer knew where to find facebook.com. Engineers had to go physically into the server rooms, where badges no longer worked. The case serves in two discussions. The first is contingent business interruption without damage. Millions of merchants who sell through Instagram or WhatsApp lost six hours of sales, with no fire and no attack, and most property policies respond only to physical damage. The second is system failure, the cyber cover that pays for a non-malicious incident. It responds for the insured whose own system goes down, rarely for one whose provider goes down, unless there is a named extension.