Even Facebook's massive-brained algos can mess up while giving directions. On October 4, the company's apps shut down for about six hours. Facebook said that the outage was due to configuration changes, but did not elaborate. Let us. Data packets use Border Gateway Protocol (BGP) to find the fastest route to a destination, the directions are held in an address book that is Domain Name Service (DNS) and the address of the destination itself is the IP address. In this case, the routing mechanism (BGP) faltered and directions went haywire (by DNS), so data was stranded in the middle of nowhere.