On October 4th, at 11:50 AM EST, all five of Facebooks services became unusable. All users attempting to access Facebook, Messenger, Instagram, WhatsApp, or Oculus received an HTTP 503 “No server is available for the request” error. Facebook’s internal infrastructure was down as well, as some employees reported not being able to use their employee badge to enter the building. Facebook reported that the outage was due to a misconfiguration in their Border Gateway Protocol (BGP) which is used to route internet traffic to the Facebook servers. Since Facebook has their own domain registrar and DNS servers, two services that assist the connection between a user and the server, this misconfiguration caused those servers to become unreachable. The outage lasted longer than usual, leading many to speculate other possibilities, such as hacking or an insider threat. Facebook maintains that this incident only occurred because of misconfigurations and was difficult to diagnose and fix because of internal outages. After almost six hours of downtime, Facebook services returned at around 5 PM EST. CTAPT analysts are actively monitoring this situation and will update with any additional information as soon as possible.