A technician has just installed a new firewall onto the network. Users are reporting that they cannot reach any
website. Upon further investigation, the technician determines that websites can be reached by entering their IP
addresses. Which of the following ports may have been closed to cause this issue?

A.
HTTP

B.
DHCP

C.
DNS

D.
NetBIOS

Explanation:
DNS links IP addresses and human-friendly fully qualified domain names (FQDNs), which are made up of the
Top-level domain (TLD), the registered domain name, and the Subdomain or hostname.
Therefore, if the DNS ports are blocked websites will not be reachable.