Rolling outages and intermittent connectivity problems hit the Internet today, thanks to a massive DDoS (Distributed Denial of Service) attack launched at DNS provider Dyn. A DDoS attack can knock out a single website or service provider by overloading their servers with garbage data and overwhelming their ability to process new connections. Affected sites include GitHub, LinkedIn, Reddit, Spotify, and Twitter. Only Facebook, which appears to have been unaffected, has kept American productivity from skyrocketing today. A wider range of sites are still accessible, but running slowly.
Dyn DNS Company is an Internet performance management company, offering products to monitor, control, and optimize online infrastructure, and also domain registration services and email products. Wikipedia
Attacking a DNS (Domain Name System) provider is a good way to knock out large swaths of the Internet. A website’s DNS address functions much like your home address. Just as your home address contains specific information to help the Post Office zero in and deliver mail to your exact location, the DNS system ensures that web traffic is routed to the appropriate location using user-friendly domain names rather than long strings of IP addresses (this is basically why you don’t need to remember the exact IP addresses of the various sites you use). The DNS system does other things — one important service it provides is translating your IP address and connecting you with a proximal server near you, which helps ensure that not all traffic has to be routed through a single point of failure. But for our purposes, the phone book analogy holds up reasonably well.
The massive DDoS launched against Dyn basically blocks the ability of other sites to read the phone book, as it were. As a result, service to the Internet has been spotty, particularly on the East Coast, as seen below (image from Down Detector, via Daily Dot).