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What is SmartCache?
SmartCache - Here's how it works: When an authoritative DNS provider suffers an outage, all of the Websites it provides service for are taken offline. They are inaccessible for everyone on the Internet. But no longer for OpenDNS users. Our servers will now immediately look for the last known good address for the site in our caches, and use that to load the site. So effectively OpenDNS users will be able to access Websites that appear down for everyone else. For our millions of users at businesses, schools and libraries around the world, saving them Internet access interruptions and the time they waste is invaluable.
Authoritative DNS outages happen frequently and can be a big problem. In March of 2009, it was reported that major authoritative DNS provider UltraDNS suffered an outage that took Salesforce.com, Amazon.com and Petco.com offline for several hours. In such a case, SmartCache fixes the inaccessibility problem and allows people to visit those sites despite the authoritative server outage.
This is just the latest in a long series of DNS innovations we've developed and passed on to you. Most recently it was blocking the Conficker worm from phoning home. By blocking the domain names the worm used, we were and continue to be able to protect people around the globe. We want our customers to know that we are committed to continually innovate and give you easy-to-use services that make your Internet experience better.
SmartCache is turned on by default for all users and only applies to queries where the authoritative server hands back a SERVFAIL response code or the query simply goes unanswered.