Which of the following is an intrusion detection system that reads all incoming packets and tries to find suspicious patterns known as signatures or rules?
Correct Answer: D
A network intrusion detection system (NIDS) is an intrusion detection system that tries to detect malicious activity such as denial of service attacks, port scans or even attempts to crack into computers by monitoring network traffic. A NIDS reads all the incoming packets and tries to find suspicious patterns known as signatures or rules. It also tries to detect incoming shell codes in the same manner that an ordinary intrusion detection systems does. Answer option A is incorrect. A host-based intrusion detection system (HIDS) produces a false alarm because of the abnormal behavior of users and the network. A host-based intrusion detection system (HIDS) is an intrusion detection system that monitors and analyses the internals of a computing system rather than the network packets on its external interfaces. A host-based Intrusion Detection System (HIDS) monitors all or parts of the dynamic behavior and the state of a computer system. HIDS looks at the state of a system, its stored information, whether in RAM, in the file system, log files or elsewhere; and checks that the contents of these appear as expected. Answer option B is incorrect. An intrusion prevention system (IPS) is a network security device that monitors network and/or system activities for malicious or unwanted behavior and can react, in real-time, to block or prevent those activities. When an attack is detected, it can drop the offending packets while still allowing all other traffic to pass. Answer option C is incorrect. A demilitarized zone (DMZ) is a physical or logical subnetwork that contains and exposes external services of an organization to a larger network, usually the Internet. The purpose of a DMZ is to add an additional layer of security to an organization's Local Area Network (LAN); an external attacker only has access to equipment in the DMZ, rather than the whole of the network. Hosts in the DMZ have limited connectivity to specific hosts in the internal network, though communication with other hosts in the DMZ and to the external network is allowed. This allows hosts in the DMZ to provide services to both the internal and external networks, while an intervening firewall controls the traffic between the DMZ servers and the internal network clients. In a DMZ configuration, most computers on the LAN run behind a firewall connected to a public network such as the Internet.
Question 52
Which of the following tools is an open source protocol analyzer that can capture traffic in real time?
Correct Answer: B
Wireshark is an open source protocol analyzer that can capture traffic in real time. Wireshark is a free packet sniffer computer application. It is used for network troubleshooting, analysis, software and communications protocol development, and education. Wireshark is very similar to tcpdump, but it has a graphical front-end, and many more information sorting and filtering options. It allows the user to see all traffic being passed over the network (usually an Ethernet network but support is being added for others) by putting the network interface into promiscuous mode. Wireshark uses pcap to capture packets, so it can only capture the packets on the networks supported by pcap. It has the following features: Data can be captured "from the wire" from a live network connection or read from a file that records the already-captured packets. Live data can be read from a number of types of network, including Ethernet, IEEE 802.11, PPP, and loopback. Captured network data can be browsed via a GUI, or via the terminal (command line) version of the utility, tshark. Captured files can be programmatically edited or converted via command-line switches to the "editcap" program. Data display can be refined using a display filter. Plugins can be created for dissecting new protocols. Answer option C is incorrect. Snort is an open source network intrusion prevention and detection system that operates as a network sniffer. It logs activities of the network that is matched with the predefined signatures. Signatures can be designed for a wide range of traffic, including Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and Internet Control Message Protocol (ICMP). Answer option D is incorrect. NetWitness is used to analyze and monitor the network traffic and activity. Answer option A is incorrect. Netresident is used to capture, store, analyze, and reconstruct network events and activities.
Question 53
Which of the following is susceptible to a birthday attack?
Correct Answer: D
Question 54
Which of the following RAID storage techniques divides the data into multiple blocks, which are further written across the RAID system?
Correct Answer: C
Question 55
John, a network administrator, is configuring Amazon EC2 cloud service for his organization. Identify the type of cloud service modules his organization adopted.
Correct Answer: B
Amazon EC2 (Elastic Compute Cloud) is a web service that provides resizable compute capacity in the cloud. It is designed to make web-scale cloud computing easier for developers. EC2's simple web service interface allows you to obtain and configure capacity with minimal friction. It provides you with complete control of your computing resources and lets you run on Amazon's proven computing environment. Amazon EC2 reduces the time required to obtain and boot new server instances to minutes, allowing you to quickly scale capacity, both up and down, as your computing requirements change. Hence, Amazon EC2 is an example of Infrastructure-as-a-Service (IaaS), which provides virtualized computing resources over the internet.
