This seems like an ineffectual measure. Instead of giving the domain to the individual nodes in the DDoS. I'd resolve it once and pound the IP until it changes.

This seems like an ineffectual measure. Instead of giving the domain to the individual nodes in the DDoS. I'd resolve it once and pound the IP until it changes. With a simple script curling the page and looking at the content to check if it's pointed to the right server. Ignoring unroutable or inane IPs returned by the DNS.