CISSP Practice

39. When constructing the communications infrastructure for moving data over a wide-area network, the major implementation choices involve decisions about all the following except which of the following?

a. Multiplexers

b. Network interface cards

c. Concentrators

d. Front-end processors

39. b. A network interface card (NIC) is used in implementing local-area networks (LANs), not wide-area networks (WANs). It is a device used primarily within a LAN to enable a number of independent devices, with varying protocols, to communicate with each other. This communication is accomplished by converting each device protocol into a common transmission protocol.

A multiplexer is incorrect because it is a device that combines the functions of multiplexing and demultiplexing of digital signals. It combines two or more information channels onto a common transmission medium.

A concentrator is incorrect because it is a device that connects a number of circuits, which are not all used at once, to a smaller group of circuits for economy. It usually provides communication capability between many low-speed, usually asynchronous, channels and one or more high-speed, usually synchronous channels. Different speeds, codes, and protocols can be accommodated on the low-speed side. The low-speed channels operate in contention and require buffering. A concentrator permits a common path to handle more data sources than there are channels currently available within the path.

A front-end processor is incorrect because it is a programmed-logic or stored-program device that interfaces data communication equipment with the input/output bus or memory of a data processing computer.

40. Network-based firewalls should perform or implement which of the following?

1. Ingress filtering

2. Egress filtering

3. Deny-by-default rulesets for incoming traffic

4. Deny-by-default rulesets for outgoing traffic

a. 1 and 2

b. 1 and 3

c. 2 and 4

d. 1, 2, 3, and 4

40. d. Because network-based firewalls can restrict both incoming and outgoing traffic, they can also be used to stop certain worm infections within the organization from spreading to external systems. To prevent malware incidents, organizations should implement deny-by-default rulesets, meaning that the firewalls deny all incoming and outgoing traffic that is not expressly permitted. Organizations should also ensure that their network firewalls perform egress and ingress filtering. Egress filtering is blocking outgoing packets that should not exit a network. Ingress filtering is blocking incoming packets that should not enter a network.

41. A website has been vandalized. Which of the following should be monitored closely?

a. Illegal logging

b. Illegal privilege usage

c. Illegal file access

d. Illegal Web server shutdown

41. c. Selecting the illegal file access addresses the vandalism issue because that is what the attacker can benefit from the most. Files have critical data useful to an attacker. The other three choices are incidental.

42. The Voice over Internet Protocol (VoIP) technology can lead to which of the following?

a. Converged network

b. Ad hoc network

c. Content delivery network

d. Wireless sensor network

42. a. The Voice over Internet Protocol (VoIP) technology can lead to a converged network, where the latter combines two different networks such as data and voice networks, similar to the VoIP. Ad hoc network is a network of nodes near each other. Content delivery network delivers the contents of music, movie, sports, and/or news from a content owner’s website to end users. Wireless sensor network is used to provide security over buildings, machinery, vehicle operation, and environmental changes in a building (e.g., humidity, voltage, and temperature).

43. Which of the following transmission media is unsuitable for handling intra-building data or voice communications?

a. Twisted pair

b. Coaxial cable

c. Optical fiber

d. Microwave transmission