CompTIA Exam Questions

Which of the following ports should be opened?

A security technician needs to open ports on a firewall to allow for domain name resolution.
Which of the following ports should be opened? (Choose two.)

A.
TCP 21

B.
TCP 23

C.
TCP 53

D.
UDP 23

E.
UDP 53

Explanation:
DNS uses TCP and UDP port 53. TCP port 53 is used for zone transfers, whereas UDP port 53 is used for
queries.