You work as the security administrator at Certkiller .com. You have been instructed to perform the
configuration which will allow only HTTP (Hypertext Transfer Protocol) traffic for outbound Internet
connections. In addition to this requirement, only specific users must have permissions to browse
the web.
Which solution should you use to enforce your requirements?

A.
Implement a packet filtering firewall.

B.
Implement a protocol analyzer.

C.
Implement a proxy server.

D.
Implement a stateful firewall.

Explanation:
A proxy server is a type of server that makes a single Internet connection and services requests
on behalf of many users. It is a server that is situated between a client and a server; that
intercessors requests. Proxy servers are used for two reasons:

* To filter requests, so a strict parent or company can prevent their kids or employees from viewing
the wrong sties.
* The increase performance, so multiple users accessing the same information (like a school, or a
library,) can fetch common information from the proxy server.
Incorrect answers:
A: A proxy server would be more suited to the needs of the company.
B: A protocol analyzer is not used to set permissions to allow only certain users access to browse
the web.
D: A stateful firewall not only examine packets at the Network layer, but also gather information
about the packet’s communications session from all layers to determine whether a packet is valid
in the context in which it is received. But this is all proxy-able.
References:
Mike Pastore and Emmett Dulaney, Security+ Study Guide, 2nd Edition, Sybex, Alameda , 2004, p
463