312-38 Sample Questions & Answers

C, D -- Explanation:
The system enters ROM monitor mode if the router does not find a valid operating system image, or if a user interrupts the boot sequence. From ROM monitor mode, a user can boot the device or perform diagnostic tests.
Answer option A is incorrect. If the router does not have a configuration file, it will automatically enter Setup mode when the user switches it on. Setup mode creates an initial configuration.
Answer option B is incorrect. Privileged EXEC is used for setting operating parameters.

C, D -- Explanation:
The system enters ROM monitor mode if the router does not find a valid operating system image, or if a user interrupts the boot sequence. From ROM monitor mode, a user can boot the device or perform diagnostic tests.
Answer option A is incorrect. If the router does not have a configuration file, it will automatically enter Setup mode when the user switches it on. Setup mode creates an initial configuration.
Answer option B is incorrect. Privileged EXEC is used for setting operating parameters.

Explanation:
EGP stands for Exterior Gateway Protocol. It is used for exchanging routing information between two gateways in a network of autonomous systems. This protocol depends upon periodic polling with proper acknowledgements to confirm that network connections are up and running, and to request for routing updates. Each router requests its neighbor at an interval of 120 to 480 seconds, for sending the routing table updates. The neighbor host then responds by sending its routing table. EGP-2 is the latest version of EGP.
Answer option B is incorrect. Internet Control Message Protocol (ICMP) is a maintenance protocol that allows routers and host computers to swap basic control information when data is sent from one computer to another. It is generally considered a part of the IP layer. It allows the computers on a network to share error and status information. An ICMP message, which is encapsulated within an IP datagram, is very useful to troubleshoot the network connectivity and can be routed throughout the Internet.
Answer option A is incorrect. Internet Group Management Protocol (IGMP) is a communication protocol that multicasts messages and information among all member devices in an IP multicast group. However, multicast traffic is sent to a single MAC address but is processed by multiple hosts. It can be effectively used for gaming and showing online videos. IGMP is vulnerable to network attacks.
Answer option D is incorrect. Open Shortest Path First (OSPF) is a routing protocol that is used in large networks. Internet Engineering Task Force (IETF) designates OSPF as one of the Interior Gateway Protocols. A host uses OSPF to obtain a change in the routing table and to immediately multicast updated information to all the other hosts in the network.

Explanation:
Source Port Address is a 16-bit field that identifies the source port number of the application program in the host that is sending the segment.
Answer option C is incorrect. This is a 32-bit field that identifies the byte number that the sender of the segment is expecting to receive from the receiver.
Answer option B is incorrect. This is a 4-bit field that defines the 4-byte words in the TCP header.
The header length can be between 20 and 60 bytes. Therefore, the value of this field can be between 5 and 15.
Answer option A is incorrect. This is a 32-bit field that identifies the number assigned to the first byte of data contained in the segment.

Explanation:
Network reconnaissance is typically carried out by a remote attacker attempting to gain information or access to a network on which it is not authorized or allowed. Network reconnaissance is increasingly used to exploit network standards and automated communication methods. The aim is to determine what types of computers are present, along with additional information about those computers such as the type and version of the operating system. This information can be analyzed for known or recently discovered vulnerabilities that can be exploited to gain access to secure networks and computers. Network reconnaissance is possibly one of the most common applications of passive data analysis. Early generation techniques, such as TCP/IP passive fingerprinting, have accuracy issues that tended to make it ineffective. Today, numerous tools exist to make reconnaissance easier and more effective.

Explanation:
The Data Link Switching Client Access Protocol (DCAP) is an application layer protocol that is used between workstations and routers for transporting SNA/NetBIOS traffic over TCP sessions. It was introduced in order to address a few deficiencies by the Data Link Switching Protocol (DLSw).
The DLSw raises the important issues of scalability and efficiency, and since DLSw is a switch-to- switch protocol, it is not efficient when implemented on workstations. DCAP was introduced in order to address these issues.

C

Explanation:
Incident response is a process that detects a problem, determines its cause, minimizes the damages, resolves the problem, and documents each step of response for future reference. One of the primary goals of incident response is to "freeze the scene". There is a close relationship between incident response, incident handling, and incident management. The primary goal of incident handling is to contain and repair any damage caused by an event and to prevent any further damage. Incident management manages the overall process of an incident by declaring the incident and preparing documentation and post-mortem reviews after the incident has occurred.
Answer option B is incorrect. The primary goal of incident handling is to contain and repair any damage caused by an event and to prevent any further damage.
Answer option C is incorrect. It manages the overall process of an incident by declaring the incident and preparing documentation and post-mortem reviews after the incident has occurred.
Answer option D is incorrect. This is an invalid option.

Explanation:
An automatic fire alarm system is designed for detecting the unwanted presence of fire by monitoring environmental changes associated with combustion. In general, a fire alarm system is classified as either automatically actuated, manually actuated, or both. Automatic fire alarm systems are intended to notify the building occupants to evacuate in the event of a fire or other emergency, to report the event to an off-premises location in order to summon emergency services, and to prepare the structure and associated systems to control the spread of fire and smoke.
Answer option B is incorrect. A fire suppression system is used in conjunction with smoke detectors and fire alarm systems to improve and increase public safety.
Answer option D is incorrect. Gaseous fire suppression is a term to describe the use of inert gases and chemical agents to extinguish a fire.
Answer option A is incorrect. A fire sprinkler is the part of a fire sprinkler system that discharges water when the effects of a fire have been detected, such as when a predetermined temperature has been reached.

Explanation:
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 D is incorrect. 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 system does.
Answer option A is incorrect. IPS (Intrusion Prevention Systems), also known as Intrusion Detection and Prevention Systems (IDPS), are network security appliances that monitor network and/or system activities for malicious activity. The main functions of "intrusion prevention systems" are to identify malicious activity, log information about said activity, attempt to block/stop activity, and report activity. An IPS can take such actions as sending an alarm, dropping the malicious packets, resetting the connection and/or blocking the traffic from the offending IP address. An IPS can also correct CRC, unfragment packet streams, prevent TCP sequencing issues, and clean up unwanted transport and network layer options.
Answer option C is incorrect. DMZ, or demilitarized zone, is a physical or logical subnetwork that contains and exposes an organization's external services to a larger untrusted network, usually the Internet. The term is normally referred to as a DMZ by IT professionals. It is sometimes referred to as a Perimeter Network. 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 any other part of the network.