ARPANET experienced a four-hour outage on October 27, 1980

On October 27, 1980, ARPANET, a predecessor of the modern internet, experienced a major outage. The network was down for four hours.

The cause was a combination of two factors: a code for detecting single errors was used when data was transmitted, but not when it was stored, and the algorithm for deleting old messages was not designed to handle one message existing with several timestamps at the same time. Together, these circumstances led to the network outage.

Image: Don DeBold from San Jose, CA, USA CC BY 2.0 · License

Translation editors: Соловьев В., Пеков А.