In this chapter, we learned about what is involved in managing the operational functions associated with use cases, that they are not DNS per se, but frequently managed from within the same scope as the DNS operations.
On their own, providing these functions for a single or small number of domains is not rocket science. Subtle issues begin to emerge when scaling into the higher orders of magnitude, such as migrating the IP address on a couple of hundred thousand URL forwarders, or relaying millions of email messages per day across thousands of domains.