Sweden saw thousands of domains go down for hours on Friday, after DNSSEC errors were introduced to the .se zone file.
Local ccTLD registry IIS said in a statement that around 8,000 domains had a “technical difficulty” that started around 1530 local time and lasted around seven hours:
On the afternoon of 4/2, a problem was discovered that concerned approximately 8,000 .se domains. The problem meant that services, such as email and web, that are linked to the affected domains in some cases could not be used or reached. In total, there are approximately 1.49 million .se domains, of which approximately 8,000 were affected.
During the afternoon and evening, a thorough work was done with the troubleshooting and the error could be fixed for the affected .se domains at approximately 22.25.
The problem is believed to have been caused by incorrect DNSSEC signatures being published in the .se zone file. Any machine using a DNSSEC-validating resolver would have seen the errors and flat-out refused to resolve the domain.
This is probably the key drawback of DNSSEC — typically resolvers will treat badly signed domains as if they do not exist, rather than fail over to an unsigned, but resolving, response.
Sweden is not a DNSSEC newbie — .se was the first TLD to deploy the technology, all the way back in 2005, with services for domain holders coming a couple of years later.
The post Thousands of domains hit by downtime after DNSSEC error first appeared on Domain Incite.