What is a limitation of TCP Wrappers?
A.
It cannot control access to running UDP services.
B.
It stops packets before they reach the application layer, thus confusing some proxy servers.
C.
The hosts.* access control system requires a complicated directory tree.
D.
They are too expensive.
Explanation:
TCP Wrappers allows you to restrict access to TCP services, but not to UDP services.
A TCP wrapper is an application that can serve as a basic firewall by restricting access to ports and resources
based on user IDs or system IDs. Using TCP wrappers is a form of port – based access control.
Incorrect Answers:
B: The problem with TCP wrappers is not that confuse proxy servers. The problem is that they do not filter UDP
traffic.
C: The hosts.* access control system does not require a complicated directory tree. In the simplest
configuration, daemon connection policies are set to either permit or block, depending on the options in file /etc/
hosts.allow. The default configuration in FreeBSD is to allow all connections to the daemons started with inetd.
D: In a UNIX/Linux system the TCP wrappers are included in the distribution and come at no cost.Stewart, James M., Ed Tittel, and Mike Chapple, CISSP: Certified Information Systems Security Professional
Study Guide, 5th Edition, Sybex, Indianapolis, 2011, p. 118