The choice of UDP as the default transport for the DNS was not a completely unqualified success. On the positive side, the stateless query/response model of UDP has been a good fit to the stateless query/response model of DNS transactions between a client and a server. The use of a UDP transport enabled the implementation of highly efficient DNS server engines that managed high peak query rates. On the other hand, these same minimal overheads imply that DNS over UDP cannot perform prompt dete...
