Today’s December 23 rd UltraDNS outage which took Amazon down is over. The UltraDNS outage taking Amazon down along with other websites tonight has ended.

Neustar runs UltraDNS. It confirmed an attack against UltraDNS sites tonight that lasted roughly 1 hour, the DNS outage the result of an attack against data centers in the Bay Area.

The outage reportedly commenced around 4:45 PM PST tonight and was resolved by roughly 6 PM tonight. Amazon reported a resolution complete at 6:40 PM PST with other sites reportedly resolved as early at as 5:40 PM.

This is the second attack against UltraDNS for 2009. But  Bill Woodcock reports the outage was wider tonight:

“This was wider than just UltraDNS.

“It’s difficult to tell at this point how much is a DDoS attack and how much is collateral damage from the attack that is being felt in other ways.

“There were routing problems at some major European exchanges at the same time that caused major Internet service providers’ routers to encounter a higher load and pass fewer packets.”