Which of the following terms refers to the method that allows or restricts specific types of packets
from crossing over the firewall?

A.
Hacking

B.
Packet filtering

C.
Web caching

D.
Spoofing

Explanation:
Packet filtering is a method that allows or restricts the flow of specific types of packets to provide
security. It analyzes the incoming and
outgoing packets and lets them pass or stops them at a network interface based on the source and
destination addresses, ports, or
protocols. Packet filtering provides a way to define precisely which type of IP traffic is allowed to
cross the firewall of an intranet. IP packet
filtering is important when users from private intranets connect to public networks, such as the
Internet.
Answer option D is incorrect. Spoofing is a technique that makes a transmission appear to have
come from an authentic source by forging the
IP address, email address, caller ID, etc. In IP spoofing, a hacker modifies packet headers by using
someone else’s IP address to hide his
identity. However, spoofing cannot be used while surfing the Internet, chatting on-line, etc. because
forging the source IP address causes the
responses to be misdirected.
Answer option C is incorrect. Web caching is a method for minimizing performance bottlenecks and
reducing network traffic by serving locally
cached Web content. Web caching helps in reducing bandwidth utilization during periods of high
network traffic. High network traffic is usually
caused when a large number of users use the network at the same time. With a caching solution in
place, users’ requests will be returned
from the cache without having to travel over a WAN link to the destination Web server.
Answer option A is incorrect. Hacking is a process by which a person acquires illegal access to a
computer or network through a security break
or by implanting a virus on the computer or network.