The internet's root servers came under a concerted distributed denial of service (DDoS) attack last week that effectively knocked three of the 13 critical pillars of the internet offline for several hours.
The attack came just days before the Janet academic network received a similar DDoS attack.
According to a first analysis of the root server attack, published by the root server operators on Tuesday, the attack occurred on November 30, 2015 between 06:50 and 09:30 UTC and then again the next day for an hour.