On 21-10-2016 there had been a widespread DDOS attack initially in the USA. This has affected service of some of our key voice and DNS service suppliers.
We monitor many sites and run monitoring ourselves and receive status updates from suppliers.
Below are some of the recent ones and some sites reporting the issue
http://www.diario4v.com/tendencias/2016/10/21/ataque-hacker-afecta-twitter-amazon-spotify-reddit-11816.html (you will need to translate)
Dyn Managed DNS advanced service monitoring is currently experiencing issues. Customers may notice incorrect probe alerts on their advanced DNS services. Our engineers continue to monitor and investigate the issue.
Customers with questions or concerns are encouraged to reach out to our Technical Support Team.
Posted 4 minutes ago. Oct 21, 2016 - 18:23 UTC
Our engineers continue to investigate and mitigate several attacks aimed against the Dyn Managed DNS infrastructure.
Posted 34 minutes ago. Oct 21, 2016 - 17:53 UTC
This DDoS attack may also be impacting Dyn Managed DNS advanced services with possible delays in monitoring. Our Engineers are continuing to work on mitigating this issue.
Posted about 2 hours ago. Oct 21, 2016 - 16:48 UTC
As of 15:52 UTC, we have begun monitoring and mitigating a DDoS attack against our Dyn Managed DNS infrastructure. Our Engineers are continuing to work on mitigating this issue.
Posted about 2 hours ago. Oct 21, 2016 - 16:06 UTC
Our upstream supplier is investigating a DNS issue, which is believed to be causing the problem.
We are now able to confirm that two nodes on our network where impacted by DNS issues between 17:13 and 17:45 today. As many of you will be aware there have been some major DOS attacks today which impacted a number of key sites at this time so we are attributing this issue to that attack.
We will continue to monitor and apologise for the inconvenience this outage has caused our customers.
As can be seen this is out of our control and is affecting many users worldwide.