Which of the following should be implemented to stop an attacker from mapping out addresses
and/or devices on a network?

A.
Single sign on

B.
IPv6

C.
Secure zone transfers

D.
VoIP

Explanation:
C: A primary DNS server has the “master copy” of a zone, and secondary DNS servers keep
copies of the zone for redundancy. When changes are made to zone data on the primary DNS
server, these changes must be distributed to the secondary DNS servers for the zone. This is
done through zone transfers. If you allow zone transfers to any server, all the resource records in
the zone are viewable by any host that can contact your DNS server. Thus you will need to secure
the zone transfers to stop an attacker from mapping out your addresses and devices on your
network.