Dear colleagues, We have been upgrading the operating system and name server software on all K-root servers. The process has mostly gone quite well, but we have had an unfortunate incident. Two of the newly upgraded nodes had been accidentally announcing the K-root prefixes even though the name server software on them was not running. This means that queries sent to these two servers between 12 and 19 January were not answered. The affected nodes are in Belgrade and Reykjavik. We estimate the percentage of queries lost to be 0.3%. Normally, failure of the name server would result in automatic withdrawal of the prefix announcements. However, this failure was caused by a flaw in the deployment process, which did not activate the correct software components in the right sequence. We have identified this issue and fixed it, so that this failure cannot happen with any future installations or upgrades. We apologise for any inconvenience caused. If you have any specific questions please send email to <dns@ripe.net>. Regards, Anand Buddhdev RIPE NCC