NANOG chatter confirming it is an issue with UltraDNS. Seems to be west coast related.
EDIT: Potentially a DOS attack. From NANOG:
"We have some DNS providing type customers (not UltraDNS) receiving a few million packets/sec of UDP/53 DoS traffic, starting at about the same time as the UltraDNS problems. No clue if it's related, but it certainly sounds suspicious. :)"
EDIT: Potentially a DOS attack. From NANOG: "We have some DNS providing type customers (not UltraDNS) receiving a few million packets/sec of UDP/53 DoS traffic, starting at about the same time as the UltraDNS problems. No clue if it's related, but it certainly sounds suspicious. :)"