ECCouncil Updated 312-38 Exam Questions and Answers by luan

The presence of packets with FIN, PUSH, and URG flags activated in network traffic, as observed through Wireshark, is indicative of a XMAS scan. This type of scan is used by attackers to identify open ports and services available on a networked computer. The peculiar combination of these TCP flags is not used in normal, everyday communications and is easily picked up by intrusion detection systems as anomalous. The XMAS scan derives its name from the fact that the packet lights up like a Christmas tree with several flags set, which is an unusual and conspicuous event in network traffic.

References: The characteristics of a XMAS scan and the use of these specific TCP flags are documented in network security literature and align with the Certified Network Defender (CND) course materials, which cover network scanning techniques and their identification123.

In Linux, to disable a user account, the usermod command is used with the -L option. This option locks the user’s password, effectively disabling the account by preventing the user from logging in. The command usermod -L alice will lock the user ‘alice’ by adding an exclamation mark (!) in front of the encrypted password in the /etc/shadow file, which is the standard method for disabling an account in Linux.

References: This information is consistent with standard Linux administration practices and is also in line with the objectives of the EC-Council’s Certified Network Defender (CND) program, which includes understanding and managing user accounts and permissions as part of network security1.

The IEEE 802.16 is a series of wireless broadband standards, also known as WirelessMAN, that are designed for Metropolitan Area Networks (MANs). It specifies the air interface, including the medium access control layer (MAC) and physical layer (PHY), of combined fixed and mobile point-to-multipoint broadband wireless access systems. This standard supports rapid deployment of broadband wireless access systems and encourages competition by providing alternatives to wireline broadband access.

References: The information is verified by the IEEE Standard for Local and metropolitan area networks Part 16: Air Interface for Broadband Wireless Access Systems1, and further details can be found in the IEEE 802.16 Working Group’s documents23.

Network sniffing is a process used to monitor and capture data packets as they travel across a network. Through network sniffing, various types of information can be obtained:

• DNS traffic: Sniffing can capture the queries and responses exchanged between DNS servers and clients, revealing which domains are being requested by users on the network.
• Telnet passwords: Since Telnet transmits data, including login credentials, in clear text, sniffing can easily capture these passwords as they traverse the network.
• Syslog traffic: Syslog is a standard for message logging, and sniffing can intercept this traffic, providing insights into the events and statuses reported by network devices.

Programming errors, however, are typically not something that can be captured through network sniffing, as they are related to the code’s logic rather than the data transmitted over the network.

References: The information provided is based on standard network security practices and the functionality of network sniffers, which are tools designed to capture and analyze network traffic. This aligns with the teachings of the Certified Network Defender (CND) course regarding network monitoring and threat detection.