It may be surprising how many sysadmins and staff at even huge companies and massive complex highly-technical deployments don't understand very much about DNS.

It may be surprising how many sysadmins and staff at even huge companies and massive complex highly-technical deployments don't understand very much about DNS. I have seen so many mission-critical deployments of various systems brought to a halt, because someone didn't configure DNS properly either on the actual nameservers or on the individual hosts.