It's nice having cheap/free DNS from people like Rackspace and Amazon, but situations like these make you realise that it's sensible to use a company like Dyn (<a href="http://dyn.com/" rel="nofollow">http://dyn.com/</a>) that are experts in highly-available DNS, rather than something that's a small part of a hosting provider's services.<p>It's easy to forget that you can have redundancy in your load balancers, web servers and databases (replication, multiple data centres, etc), but DNS is how you're found by the rest of the Internet.<p>No DNS resolution = no one reaches your expensive, lovingly-crafted infrastructure.