The root servers of the Domain Name Systems are highly redundant. This redundancy is important to ensure that the root DNS service continues to be provided even if one of the DNS root servers fails. These servers are well maintained and fail rarely. However, on October 1st, the H instance of the root DNS servers maintained by the US Army failed. The failure was caused by the loss of an optical fiber due to flooding in the US. The H instance is one of the few root servers that is not replicated and does not use anycast.

The DNSMon service maintained by RIPE provides additional statistics about this failure.