Which of the following is a tool often used to reduce the risk to a local area network (LAN) that has external
connections by filtering Ingress and Egress traffic?

A.
A firewall.

B.
Dial-up.

C.
Passwords.

D.
Fiber optics.

Explanation:
Egress filtering is the practice of monitoring and potentially restricting the flow of information outbound from one
network to another. TCP/IP packets that are being sent out of the internal network are examined via a router,
firewall, or similar edge device.
Similarly, ingress filtering is used to ensure that incoming packets are actually from the networks from which
they claim to originate.
Incorrect Answers:
B: Egress and ingress filtering can be implemented on a firewall, but not through dial-up.
C: Egress and ingress filtering can be implemented on a firewall, but not through passwords.
D: Egress and ingress filtering can be implemented on a firewall, but not fiber optics.

Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, New York, 2013, p. 631