Boom Goes the "Dyn"amite
by Alec Pinkham Alec Pinkham on

The internet crashed today. It wasn’t the normal WiFi reset, network congestion, single-site outage or even the obscure mouse-ate-the-cable. The east-coast internet was under attack due to a DDoS attack that took down Dyn, a leader in DNS services for much of the east coast of the United States. Dyn’s status page has been kept running to keep the public aware of the situation and many internet reporters have also been following the play-by-play.


What is DDoS, Again?

Distributed denial-of-service attacks are common and their behavior well-documented, but reports have indicated that the size of these attacks has been growing in recent years. The attack is created by targeting Domain Name Servers (DNS), which act as the Contacts list for the internet. Much like we’ve all forgotten even our closest friends' phone numbers, the IP addresses of the internet are varied and dynamic. DNS translates that to something easier to read (e.g., By targeting the DNS with so much traffic that it can’t respond to normal traffic, the attacker effectively crashes that link. For a handy animation, check this out.


"Starting at 11:10 UTC, on October 21st-Friday 2016, we began monitoring and mitigating a DDoS attack against our Dyn Managed DNS infrastructure. Some customers may experience increased DNS query latency and delayed zone propagation during this time. Updates will be posted as information becomes available," according to Dyn's website.

Starting Friday morning around 7, the attack started or reached critical mass enough to affect wider service. Popular sites known to be affected were Twitter, Spotify, Reddit and many others including news sites like The New York Times. Dyn restored service just after 9am. The servers fell over again around noon as the result of another attack.

As of 3pm, much of the east coast was still affected, with Dyn-specific issues highly focused in the northeast.

Dyn reported issues from

A view of Level3, a large internet service provider, shows a darker picture of the northeast in what can only be described as a bleak picture of the area of effect this attack has had.

Level3 reported outage from

While not much is known about the attack as a whole, the surface area is impressive, if not also terrifying. This attack may or may not be connected to the larger Internet of Things attack that occurred a few weeks ago. The same method could have been used for these DDoS attacks which uses webcams, refrigerators and other devices that connect to the internet as “zombies” to relentlessly ping DNS servers when given the command. Known recently as a Mirai botnet, there are early indications that this style of attack is what has taken Dyn down today

We’ll be looking into the data we’ve captured and be updating you on Monday with the range of visibility that AppNeta can offer.

Filed Under: Industry Insights

Tags: internet outages , web outages