Reiko works for an ISP where she must implement a DNS server that will host multiple company
domains. Which type of DNS server must she install?

A.
Root.

B.
Caching

C.
Primary.

D.
Forwarding.

Explanation:
When a domain is hosted, it is registered with a domain registry, and is added to the root servers.
When a user wants to access the domain, the root server forwards the request to the DNS server
that has been registered. If these are independent domains that are not subbed off the ISP’s
domain root, then these references should point directly to the DNS servers on the company’s
intranet.
Some companies are small, and do not run their own DNS servers. So what they will do is have
the ISP run the DNS servers, and this is the process of hosting a DNS server for someone else.
The DNS server receiving the requests, at the company’s intranet, will normally be a primary zone
DNS server,

Incorrect Answers:
A: AN ISP does not create a ROOT server. This is reserved by the various Internet Registry
entities, responsible for updating and maintaining the root DNS servers. In North America, this
would be InterNIC.
B: A caching server has no information in it. It builds information by requesting the required
information, as requests are made, from other DNS servers. At least a primary DNS server with
the information must be present, and at this point of entry, we need a primary zone DNS server.
D: The request received by the root is already forwarded. The type of server needed to host the
DNS at this point need to be a primary zone DNS server.