Having trouble accessing a favorite Web site? Perhaps the site was taken
offline, or the computer hosting it is down for maintenance.
However, the cause could be something more mysterious. At any given moment, a
portion of Internet traffic ends up being routed into information
"black holes." These are situations where
advertised paths
exist to the destination, but messages - a request to visit a Web site, an
outgoing e-mail - get lost along the way.
Hubble is a system that operates continuously to find persistent Internet
black holes as they occur.
Hubble has operated continuously since September 17, 2007. During that time, it identified 959,702 black holes and reachability problems. In the most recent quarter-hourly round, completed at 15:14 PDT, 05/13/2008, Hubble issued 91,617 traceroutes to 4,459 prefixes it identified as likely to be experiencing problems (of 78,772 total prefixes monitored by the system). Of these, it found 3,132 prefixes to be unreachable from all its vantage points and 1,008 to be reachable from some vantage points and not others.
Below the following map, you'll find instructions
on interpreting and navigating this page. You can go
here
for a more detailed description of the Hubble academic research
project and its goals. Below, you can look upHubble's current view of the reachability of the address of your
choice. Feel free to send suggestions and other feedback to
hubble-support.
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