Hundreds of thousands of web sites were slowed for hours today when Network Solutions' DNS servers were hit by a distributed denial of service (DDoS) attack.
"There is a spike in DNS query volumes that is causing latency for the delay in web sites resolving," Networks Solutions said on its blog. "This is a result of a DDOS attack. We are taking measures to mitigate the attack and speed up queries." Posts on network operator mailing lists decribed the issue as a "very large scale" attack.
UPDATE: "DNS queries for web sites should be responding normally," according to an update from Network Solutions at about 10:30 pm Eastern. "As always, we will continue to work to take measures to prevent these and other types of technical issues caused by third parties that may impact our customers."
This isn't the first time a DDoS attack has disrupted a domain registrar's DNS servers. A 2006 attack on the nameservers for German registrar Joker left about a half million domains unavailable for days. In 2002 the Internet's root nameservers came under attack, with the DDoS causing network congestion but only minor performance problems for the DNS system.