Monday night was a dark time for Internet users in Sweden. For about an hour the Swedish Internet failed, meaning it was impossible to access any websites with a domain name ending in .SE (that’s about 900,000 domains folks). No one seems to know how the problem occurred, except that it happened during routine maintenance work. It makes you wonder how easy it would be to shut down the whole Internet.
Even Danny Aerts, the CEO for .SE, told Swedish news agency TT that he wasn’t sure how the error occurred, but that the problem is being investigated.
The bloggers at Royal Pingdom think they might have figured it out. According to them the .SE registry used an incorrectly configured script to update the .SE zone. Apparently a single ”.” wasn’t being added to the data. It’s one of those pesky little coding mistakes that might keep you up for hours wondering why your new java game isn’t working, but shouldn’t be missed by top level engineers responsible for the whole Swedish Internet. Apparently the error led to an extra .SE being added to the end of Swedish URLs.
DNS lookups for .SE domains started failing at around 21:00 local time and the bug was fixed an hour later. However according to Royal Pingdom Swedish websites are still having problems, since DNS lookups are cached externally by Internet service providers and web hosting companies. The ISPs both in Sweden and other countries will have to reset their caches to allow the domains to start working normally again.