The outages on Facebook, WhatsApp and Instagram on Monday are likely due to a problem with the company’s domain name system, an obscure but important component of the Internet.
Commonly known as DNS, it is like a phone book for the Internet. This is the tool that converts web domains like Facebook into the actual Internet Protocol or IP address where the site resides. Think of Facebook as the person that might appear in the white pages, and the IP address they would find as the physical address.
On Monday, a technical issue related to Facebook’s DNS records caused a disruption of at least six hours. When a DNS error occurs, the user’s web browser or smartphone app can navigate Facebook services for a long time.
Not only did Facebook’s primary platform fall down, but some of its internal applications also declined, including the company’s own email system. Users on Twitter and Reddit have also said that employees at the company’s Menlo Park, California, campus were unable to access offices and conference rooms, which required security badges. This can happen if the system providing access is also connected to the same domain – Facebook.
Facebook’s problem appears to have originated in the Border Gateway Protocol, or BGP. If DNS is the Internet’s phone book, then BGP is its postal service. When a user enters data into the Internet, BGP determines the best available path that the data can travel.
According to Cloudflare chief technology officer John Graham-Cumming, minutes before Facebook’s platform loaded, public records show that a large number of changes were made to Facebook’s BGP routes. Facebook has not commented on why these changes were made or not.
However, Cloudflare chief executive Matthew Prince tweeted later on Monday that public data showed those BGP routes “are being republished. It is likely that service is on track to be restored.”
seeing @FacebookBGP announcements are getting published again. It is likely that the service is on the way to be restored.
– Matthew Prince ????? (@eastdakota) 4 October 2021