Which of the following devices would be the MOST efficient way to filter external websites for staff on an
internal network?

A.
Protocol analyzer

B.
Switch

C.
Proxy

D.
Router

Explanation:
A proxy is a device that acts on behalf of other devices. All internal user communications with the Internet
could be controlled through a proxy server, which can be configured to automatically filter out or block
certain sites and content. It can also cache often-accessed sites to improve performance.
Incorrect Answers:
A: A protocol analyzer is a packet capturing tool that can collect network traffic. Most analyzers typically
offer both capture filters, which specifies which network packets should be saved to the capture file or
buffer, and display filters, which can be used to find captured network packets of interest. It does not
block network packets.
B: A switch is a network device that connects many other devices together. The switch uses a media
access control (MAC) addresses table pass network traffic it receives to the intended recipient. It does not
offer other sniffing, filtering or blocking features.
D: A router is a network device that connects several network segments. It allows traffic to flow from one
network segment to another by using a routing table. It does not offer other sniffing, filtering or blocking
features.

Dulaney, Emmett and Chuck Eastton, CompTIA Security+ Study Guide, 6th Edition, Sybex, Indianapolis,
2014, pp.102, 103, 118
Stewart, James Michael, CompTIA Security+ Review Guide, Sybex, Indianapolis, 2014, pp. 8-9, 9-10, 11, 18