A problem during routine maintenance of Sweden's top-level domain, .se, took down the Internet for the country for about an hour on Monday night.
Basically, the .se registry used an incorrectly configured script to update the .se zone, Sweden-based Pingdom, which monitors Web site performance, wrote in a blog post on Tuesday. A period was dropped at the end of DNS domain name system records for the Swedish top-level domain, breaking the entire DNS lookup chain.
What this meant was that Web sites ending in .se could not be accessed and e-mail to Swedish domain names stopped working. For some sites the problems will take longer to resolve because of the fact that DNS lookups are cached externally and those servers had to be flushed, Pingdom said.
There are more than 900,000 .se domain names and every one of them was affected, the company said.