[outages] Neustar UltraDNS sporadic resolution failure

Seeing repeated failures on both udns1.ultradns.net and udns2.ultradns.net. Getting some initial corroboration from several folks on twitter, but no acknowledgement from Neustar. ; <<>> DiG 9.8.3-P1 <<>> @udns2.ultradns.net www.braintreegateway.com ; (1 server found) ;; global options: +cmd ;; connection timed out; no servers could be reached