It's been an interesting few days thanks to the rather large denial of service attack on the internet's root servers. Although all thirteen servers were nominally hit, the attack had less effect on the net than the 9/11 attacks when anyone online simply swamped the net looking for a news feed. Which is encouraging.
What interested me more was the amount of information provided by the maintainers of those servers who fared better than others on how their root server works and how it coped. For those interested, have a look at http://www.isc.org/ops/f-root/ for details of just one and this presentation...