Facebook’s entire network, which includes Instagram and WhatsApp, went offline today. On Twitter, Facebook posted the following statement: “We’re aware that some people are having trouble accessing our apps and products. We’re working to get things back to normal as quickly as possible, and we apologize for any inconvenience.”
Facebook's Twitter Post Regarding the Network Outage
The network outage was due to a DNS problem. Facebook's domain names stopped resolving, and their infrastructure IPs were unreachable because their DNS servers were unreachable. It was as if someone had "pulled the cables" from their data centers all at once and disconnected them from the Internet.
What is DNS (Domain Name System)?
The Domain Name System (DNS) is an important part of the internet, providing a way to map names (a website you’re seeking) to numbers (the address for the website). Anything connected to the internet - laptops, tablets, mobile phones, websites - has an Internet Protocol (IP) address. Your favorite website might have an IP address like 93.184.216.34, but this is obviously not easy to remember. However, a domain name such as example.com is something people can recognize and remember. DNS maps domain names with IP addresses enabling humans to use memorable domain names while computers on the internet can use IP addresses.