Sweden Removed from the Internet for One Hour Following ccTLD Maintenance

A maintenance error on Monday night led to Sweden’s country code Top Level Domain, .SE, being removed from the internet for about one hour meaning all .SE domain names were unavailable worldwide..SE (The Internet Infrastructure Foundation), the registry for .SE, sent out an incorrect zone file on Monday 12 October at 21.45 in connection with planned maintenance work. The cause was an incorrect software update, which, despite .SE’s testing procedures was not detected.The problem, promptly resolved, continued to impact on some internet users worldwide as some internet service providers outside of Sweden who are unaware of the problems may need to clear their cache.According to Pingdom “it wasn’t until around 23:30 local time[Monday] night that the major Swedish ISPs had flushed their own DNS caches, meaning that they cleared away the broken results so that new DNS lookups could start working properly again. If they had not done this the problem would have remained for a full 24 hours.”There are still a large number of smaller ISPs that have not yet fixed the problem. It is also likely that ISPs outside of Sweden is not aware of the incident, so the effects of the problem may remain there as well.”According to investigations by Pingdom, when .SE was “updating the data, the script did not add a terminating ‘.’ to the DNS records in the .se zone. That trailing dot is necessary in the settings for DNS to understand that ‘.se’ is the top-level domain. It is a seemingly small detail, but without it, the whole DNS lookup chain broke down.”To read the Pingdom report in full, see:
royal.pingdom.com/2009/10/13/sweden’s-internet-broken-by-dns-mistake/A statement from .SE on the outage is available from:

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