Facebook went down for hours today, affecting Oculus headsets

Update: As of 3:30 pm PDT, Facebook, Instagram, and related websites appear to be working, including oculus.com and the Oculus app. Services are "coming back online now," the company tweeted at 3:33 pm. 

Facebook says that today's extended outage did not compromise user data—it was actually a pretty boring networking error. 

"Our engineering teams have learned that configuration changes on the backbone routers that coordinate network traffic between our data centers caused issues that interrupted this communication, the company posted on its blog. "This disruption to network traffic had a cascading effect on the way our data centers communicate, bringing our services to a halt."

Original story: Facebook users from around the world are unable to access the social network today, seemingly because the domain name "facebook.com" has temporarily gone missing. The outage began at around 8:30 am Pacific, and continues nearly five hours later.

The error "DNS_PROBE_FINISHED_NXDOMAIN" appears when attempting to load the Facebook website, which means that the service responsible for translating "facebook.com" into an IP address can't do it. Instagram and WhatsApp are also unreachable. 

"We're aware that some people are having trouble accessing our apps and products," wrote Facebook on Twitter. "We're working to get things back to normal as quickly as possible, and we apologize for any inconvenience."

Facebook owns VR headset maker Oculus, and controversially requires Oculus Quest users to log in with a Facebook account. In numerous Reddit threads, many Quest owners say they have been able to use their headsets during the outage—to play VR games on Steam, for instance—but some say they can't load their Oculus libraries, and those who just took a Quest 2 out of the box have reported that they're unable to complete the initial setup.

"We're aware that some people are having trouble accessing our apps and products," Oculus wrote in one thread. "The teams are hard at work getting things back to normal as quickly as possible, and we apologize for any inconvenience."

When I launch the Oculus PC application, it says that it detects no internet connection. The Oculus website is also down.

At around 1 pm Pacific, Facebook CTO Mike Schroepfer tweeted that the outage is being caused by "networking issues." That's as much as Facebook has said about the cause of the problems.

The simplest potential explanation is that someone screwed up. A now-deleted Reddit post from a person who claimed to have inside knowledge of the situation said that the issue was being caused by a BGP configuration error which required physical hardware access to repair.

The more dramatic theory is that a person or group has intentionally taken Facebook down, but there's currently no evidence to suggest that an attack has occurred despite all the speculation on social media sites (excluding Facebook). The timing of the outage may be pushing speculation in that direction: Yesterday, the whistleblower who recently leaked internal Facebook documents to the Wall Street Journal appeared on 60 Minutes to discuss her claim that the company chooses profits over curbing hate speech and misinformation.

Whatever the cause, it's apparently a doozy of a malfunction. It isn't just the Facebook website and apps that are unreachable: Facebook employees reportedly can't access the company's internal communication systems, and according to New York Times tech reporter Sheera Frenkel, even Facebook's door badges have been affected, preventing employees from entering buildings.