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.