Free DNS servers ns1.cloudns.net, ns2.cloudns.net, ns3.cloudns.net and ns4.cloudns.net are under a large DDoS attack. We work to mitigate it.
We will keep you updated. Sorry for the inconvenience.
[Update 2014-03-24 8:00CET] DDoS attack is mitigated on ns1.cloudns.net. We work to mitigate it at all.
Regards,
ClouDNS Team