Check out this animation on the damage super storm Hurricane Sandy inflicted Internet-wise. Here you see Hurricane Sandy Internet outage data for New York City, Long Island, New Jersey and the eastern seaboard of the United States as far south as Washington D.C. and as far north as the I-93 corridor linking Boston to New Hampshire.
According to the folks at Renesys, which created the above animation, each square represents “the fate of a set of networks geo-located within a common tenth-degree square of the Earth’s surface.”
Renesys blogger James Cowie goes on to explain:
At one end of the scale, the darkest green indicates better than 99.95% of the networks are available. At the other end, solid red indicates that more than 5% of the networks at that location have been removed from the global routing table, meaning that they can’t be reached by anyone.
Five percent doesn’t sound like much, but consider the Internet density in the affected areas In fact, Manhattan’s outage rates were much higher — on the order of 10 (percent), which is impressively low given the fact that ConEd cut power to much of the island. Silencing ten percent of the networks in the New York area is like taking out an entire country the size of Austria, in terms of impact on the global routing table. The 90% that survive are in data centers, running on generator power supplied by engineers who do not sleep much.
So the Internet becomes a sensing network in its own right — via a combination of human assisted and computer downtime reporting.
This Renesys view shows network outages by state over time. New York — with around 1,200 networks offline at the peak — is at the top of the list.
Using Twitter and other sources, Rich Miller of the Data Center Knowledge blog includes excellent in-depth reporting on data center outages.
Flooding and power failures most frequently cause the Internet outages we see. Con Edison, which serves Manhattan, and the Long Island Power Authority, generated the following reports in aggregate and mapped them in real time. Note the overlap.