What is a delegated zone in DNS and how does it work?
A delegated zone is a subdomain hosted by a separate set of DNS servers, Delegated zones are usually administered by a separate set of administrators too.
Example: college.edu —> engineering.college.edu
where “engineering.college.edu” is a sub-domain to the parent domain “college.edu” and is entirely owned and managed by a separate administrative group.
Queries sent to the servers at the parent zone (college.edu) will return a referral to the name servers of the delegated zone (engineering.college.edu).
Delegation is what glues the global DNS name space together. When you ask the parent name server for details of a record beneath their domain that has been delegated to another set of name servers, it will return a referral of where to ask next.