From 13:30 through about 14:50 today, large parts of the .de zone where unavailable, causing most if not all of the 13 million .de domain names with websites and e-mail to be unavailable. It is very uncommon for a large domain name extension to be fully unavailable, so much that it is causing domain names under that TLD to actually not work. In the last 5 to 10 years, as far as we know about, of all the large TLD’s only .nu, .se and .biz have known some real downtime.
Insiders tell us that the nameserver infrastructure that is being used by DENIC is somewhat out-dated and certainly not in line with the requirements of a large TLD like .de. DENIC would still be using a mixure of the standard version of “BIND” and “NSD” as their nameserver software. While both are known to be very robust and stable, they do in some ways lack in support for very large zones like that of a country code TLD.