AIT 542 Final Exam 112 Questions with Verified Answers,100% CORRECT, Exams of Information and Communications Technology (ICT)

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AIT 542 Final Exam 112 Questions with Verified Answers

Signal 9 - CORRECT ANSWER The one signal no nix (Unix based) process can catch or ignore is __________. False - CORRECT ANSWER True or False: Bit rate and baud rate are always the same. 1 - CORRECT ANSWER (3 x 7) Mod 2 = False - CORRECT ANSWER True or False: Under the ''simple security'' policy, users can read any file but only write to files of lower security/privilege level. True - CORRECT ANSWER True or False: Multi-Level Security (MLS) requires that all classified information be keep on completely separate, air-gapped systems.

• CORRECT ANSWER A NAT gateway with IP address 129.174.1.13 receives from an internal host on the LAN for which it is the gateway, a request containing this information:src addrs src port dest addrs dest port192.168.1.5 52760 132.160.81.2 80 Show what this information would look like on the 'other side,' i.e., the Internet side, of the NAT gateway as it passes through to the internet : src addrs: src port: dest addrs: dest port: the most well-known variants are signature-based detection (recognizing bad patterns, such as malware); and anomaly-based detection (detecting deviations from a model of "good" traffic, which often relies on machine learning), another is reputation-based detection (recognizing the potential threat according to the reputation scores). - CORRECT ANSWER A ''statistical anomaly detector'' is one tool that can be used for intruder detection. Using such a tool, how would you detect an intruder, i.e., how would you suspect there was an intruder on the system?

False - CORRECT ANSWER True or False: Files are stored on a hard disk as one contiguous stream of data in adjacent, connected sectors. -Type "(1)" in question: this RAID configuration is best suited to very high speed data transfers to/from disk-Type "(2)" in question: this RAID configuration is best suited for handling large numbers of simultaneous requests for the disk's content. - CORRECT ANSWER RAID arrays combine multiple disk drives to create the impression of one, large disk. This can be done in two main ways: (1) the disk arms and platter rotations are synchronized across all disks in the RAID, (2) the disk arms and platters all operate independently among the disks in the RAID. Briefly describe what each of these designs is best for, i.e., what kind of I/O requirements are best served by using each of these two different designs? Such resident frames are used to hold the OS kernel: code that must always be in memory. - CORRECT ANSWER In systems using virtual memory, some memory frames are made permanently resident i.e., pages loaded into those frames can never be paged out to make space for resolving a page fault. Of what use would such 'resident frames' be to the OS?

• ID
• Broadcast - CORRECT ANSWER In any network address space, the first and last addresses are always reserved. The first is reserved for the network ________ and the last is reserved for the network ________. Internet Engineering Task Force (IETF) - CORRECT ANSWER Internal standards are documented in Requests for Comment (RFC) issues by: logic bomb - CORRECT ANSWER A program that works normally but contains code that 'explodes' (e.g., causing damage to data or services) when a certain event occurs is called a(n):
• In favor: easy to adapt/customize since you have the source code independence from a particular vendor and its product release and bug fix schedules

• Against: Expensive personnel: open source requires more specialized personnel to operate and maintain it, hence more expensive - CORRECT ANSWER The decision to use open source software is often contentious. Briefly describe: (1) one argument in favor of adopting open source software, (2) one argument against using open source software. True - CORRECT ANSWER Both Ethernet and ordinary user terminals actually use serial data transfer. library - CORRECT ANSWER A __________ is a collection of precompiled routines that a program can use. assign them names - CORRECT ANSWER The best way to handle constants in a computer program is to: names - CORRECT ANSWER Giving __________ to constants is the preferred method for handling them in a program. False - CORRECT ANSWER True or False: Only proprietary software requires you to accept the terms of a license in order to use the software. socket - CORRECT ANSWER Host IP address + port number = __________. *True - CORRECT ANSWER True or False: ext3 and NTFS are both journaled file systems True - CORRECT ANSWER True or False: In a RAID implementation, disks may be either fully independent or synchronized. True - CORRECT ANSWER True or False: Apache, the most popular web server software on the planet, is open source software.
• access rights per user*
• access rights per resource* - CORRECT ANSWER An Access Matrix is a combination of an Access Control List (ACL) and Capability Tickets. Together these provide:

• http: 80
• pop3: 110
• smtp: 25
• ftp: 21
• imap2: 143
• ssh: 22 - CORRECT ANSWER Match commonly used ports to their respective services. http
• http
• pop
• smtp
• ftp
• imap
• ssh
• made up of multiple platters on a single spindle
• use magnets / magnetic fields to erase data - CORRECT ANSWER Conventional harddisk drives are:
• 100
• 4000 KB - CORRECT ANSWER - Suppose a hard disk has 4 platters. Each platter's two surfaces are formatted to have 100 tracks, and each track has 10 sectors. How many cylinders are there on this disk?
• If each sector can hold 512 bytes (that's half of 1 Kilobyte), what is the storage capacity of the disk?
  • CORRECT ANSWER Briefly explain how to permanently delete a file from a conventional hard disk in Windows. interrupt handler - CORRECT ANSWER When an interrupt is taken by the OS, the OS runs this to deal with the interrupt __________.

baseline - CORRECT ANSWER In profile based, statistical anomaly detection, we typically compare a user's profile or usage date to an established __________.

• CORRECT ANSWER - a program must be loaded into real memory at exactly the location it was built for
• programmer uses real addresses in the source code
• not good for multi-user / multi-tasking systems
• variables are associate with real memory addresses at the load module is 'bound' to the location where it is loaded
• variables are associated with real memory addresses at run time
• loads a program into real memory keeping relative addresses as they are masquerading - CORRECT ANSWER Pretending to be an authorized user in order to gain access to system resources for which you are not authorized is known as a __________attack.
• stdin - associated with the keyboard
• stdout - associated with the display
• stderr - associated with a display - CORRECT ANSWER Normally, a process begun from a controlling TTY has three files open for it. Identify the files and their functions from the list below.
• seek delays
• rotational delays - CORRECT ANSWER Which of the following are typical delays commonly associated with hard disk drives? hash - CORRECT ANSWER A system should never store passwords in plaintext. Instead, passwords are typically stored in a short, encrypted file know as a _________ of the password. polymorphic - CORRECT ANSWER Malware that mutates with each new copy to prevent a recognizable signature are said to be __________.

Linux - CORRECT ANSWER Most of the "super computers" that we discussed run which operating system.

• Java
• C++ - CORRECT ANSWER Which of the following could be considered a "high level language?" (Select all that apply.)
• Java
• Assembly
• C++
• Fortran True - CORRECT ANSWER True or False: Routers always route traffic via the shortest path. 128 - CORRECT ANSWER IPv4 has 32-bit addresses. In contrast, IPv6 has ______ - bit addresses thus allowing for significantly more usable addresses.
• 16
• how ever many are left over - CORRECT ANSWER Assume GMU internet addresses can be expressed as 129.174/16.
• How many bits are available for network addresses?
• How many bits are available for host addresses? critical section - CORRECT ANSWER An area of code that must not be simultaneously accessed by more than one process is a(n) __________. i node - CORRECT ANSWER A Unix-style data structure that describes a filesystem object is known as a(n) __________.
• Ethernet: Yes
• Serial Terminal: No
• Disk: Yes - CORRECT ANSWER We saw that DMA is a feature computers offer certain peripheral devices for the transfer of their data. Which of these controller devices would you expect uses DMA?

A. Ethernet B. Serial Terminal C. Disk D. Graphics Cards True - CORRECT ANSWER True or False: A Domain Name Server (DNS) can be thought of as the internet's version of a phone book. framing - CORRECT ANSWER Collecting some number of bits together as a package is known as __________. tracks - CORRECT ANSWER Magnetic disks are typically divided into axial rings known as __________. head - CORRECT ANSWER Imposing a magnetic field on a magnetic medium is accomplished by a __________. An interpreter translates a higher level language into machine code one line at a time - CORRECT ANSWER The main difference between an interpreter and a compiler is: False - CORRECT ANSWER True or False: A disk can only have one filesystem on it.

• 1
• 0 - CORRECT ANSWER The number of errors in a byte of data that parity can detect is _____________ and it can correct how many ________________. fragmentation - CORRECT ANSWER Files are generally broken up into pieces to fit on a disk drive. The result is a state known as disk __________ which makes the system work harder and takes longer to read and write. Network - CORRECT ANSWER Routers typically operate at layer 3 of the ISO/OSI reference model. This layer is also know as the __________ layer. True - CORRECT ANSWER True or False: Multipurpose Internet Mail Extensions (MIME) provides a way to encode binary data using only printable ASCII characters.

Signal - CORRECT ANSWER What is the 'complementary' semaphore operation to wait(s)? __________ True - CORRECT ANSWER True or False: The term "High-Level Language" refers to computer languages that are more easily read by humans. disk drives - CORRECT ANSWER SCSI and ATA (or SATA) are used when connecting or talking about __________. UART (universal asynchronous receiver/transmitter) - CORRECT ANSWER Input / output (I/O) devices typically interface with computing platforms through a device that handles serial transmission / reception. This device is known as a(n) __________. (The acronym is sufficient.) worms - CORRECT ANSWER Of all the different types of malware, most malware today is/are __________.

• SCSI
• SATA - CORRECT ANSWER The two most popular disk controller standards in use today are ___________ and. ____________. worms & viruses - CORRECT ANSWER Name two types of malware that replicate.
  • CORRECT ANSWER Our organization adheres to a rigid data backup schedule. All files are backed up every Sunday at 1AM (a full backup). Every other day of the week (Mon-Sat) an incremental backup is completed at 1AM. The systems fails at 9AM on Tuesday. In order to recover the maximum amount of lost data the recovery process should proceed as follows. List which backups should be restored, in order.
• Sunday
• Monday
• Tuesday
• Wednesday
• Thursday
• Friday
• Saturday

• What data will be lost, if any?
• lack of support
• legal issues over licensing - CORRECT ANSWER Typical criticisms of Open Source Software include: DVD - CORRECT ANSWER Layer change time is a data transfer delay typically associated with __________. do - CORRECT ANSWER A system "doorman" will typically allow access to users based on something you know, something you have, something you are and/or something you __________. external - CORRECT ANSWER Dynamic partition allocation schemes suffer from __________ fragmentation.

1. B
2. A
3. C. - CORRECT ANSWER Match the following with the most accurate description. No responses should be used more than once.

• A. Interpreter
• B. Compiler
• C. Assembler

1. translates source code to machine language completely before the program is loaded to run
2. translates source code to machine language statement by statement as the program runs
3. translates assembly language into machine language all source code contained in the libraries - CORRECT ANSWER No linking is needed when:
   • CORRECT ANSWER A user is working on a computer (could be running Windows XP or *nix). At some point the user deletes a file. Deleting the file does not cause

the actual data that was in the file to be deleted (erased) from the disk: what does deleting the file do? When does the data from the deleted file actually get deleted? Deleting a file simply causes the disk blocks allocated to the file to be marked as available for reuse. The content of the disk blocks are not altered, so the former file's content persists. Only when the blocks are allocated to a new file and overwritten will the previous file's contents be eliminated. - CORRECT ANSWER Suppose you want to send a message to another node using IP. Your message is 5,000 bytes long but the maximum transfer unit of the network you use is 1, bytes. How many packets will you actually send? True - CORRECT ANSWER True or False: Open source software is not licensed so that anyone may use and/or modify it. True - CORRECT ANSWER RAID4 can continue to provide correct data operation even if one of its disk fails completely. packet - CORRECT ANSWER The basic data unit in the Transmission Control Protocol is called a(n) __________. random - CORRECT ANSWER Access to a file can be sequential or __________. Network Address Translation (NAT)

• Translates the private IP address to a public address for routing over the Internet
• sends variety of packets with many ephemeral port numbers - CORRECT ANSWER Define NAT and briefly describe what it does. meaning that its power spectral density is nearly equal throughout the frequency spectrum - CORRECT ANSWER Why is thermal noise in a channel called ''white'' noise?
• rotational delay
• seek delay - CORRECT ANSWER Magnet and optical disk drives have two basic kinds of delay in common. Optical disks, have two additional sources of delay. Name these two additional sources of delay experienced by optical drives only:

True - CORRECT ANSWER True or False: Software Engineering is a discipline devoted to best practices in design and building of computer programs. False - CORRECT ANSWER An operating systems generally does not talk directly to disk drives.

• CORRECT ANSWER Suppose a program takes 1000 machine instructions to run from start to end, and can do that in 10 microseconds when no page faults occur. How long will this same program take if 1 in every 100 instructions has a page fault and each page fault takes 100 milliseconds to resolve?[???????] Beowulf Cluster - CORRECT ANSWER Wiglaf and Hygelac were early versions of this popular, open-source cluster architecture __________. True - CORRECT ANSWER True or False: A virus differs from a worm in that a virus needs a program to be a 'carrier' in order for it to spread, but a worm does not. link library object code with newly created object code - CORRECT ANSWER What does the linker do? 10 bits - CORRECT ANSWER Suppose a system uses 1024-byte pages: how many address bits are needed for the offset onto a page? (Hint: 1024 = 210 ) __________. Requires processes to request ALL of its resources before it begins. Blocks all processes until all its requests can be granted. - CORRECT ANSWER Briefly explain how "Stop & Wait" manages the transmission of frames from sender to receiver. machine code translated into named functions - CORRECT ANSWER Assembly language refers to: A page table's purpose is to provide the correspondence between a page number being looked-up and the frame in real memory where that page is stored - CORRECT ANSWER What is the purpose of a page table?
• decrement semaphore count

• if s count is < 0, block invoking process - CORRECT ANSWER In using semaphores to control access to a critical section, a process will perform a wait(s); at which point one of two things will immediately happen. Briefly describe those two things. Polymorphic viruses will make slightly different versions of themselves each time they replicate to defeat system countermeasures - CORRECT ANSWER Antivirus software works by recognizing some signature that is characteristic of a virus' presence. Why are polymorphic viruses harder than other kinds for antivirus software to recognize? False - CORRECT ANSWER True or False: Network-accessible servers can only provide information to clients (i.e., static or dynamically generated files). False - CORRECT ANSWER True or False: Solid state drives potentially suffer from all the same delays as typical magnetic hard drives.
• seek time
• rotational delay - CORRECT ANSWER Average latency can be calculated as the average ________________ plus the average __________________. True - CORRECT ANSWER True or False: Most ASCII codes are represented on screen as a specific character. But some are interpreted to perform some action. sectors - CORRECT ANSWER Hard drives are typically divided into wedges know as __________. True - CORRECT ANSWER True or False: Machine code, op code, and assembly language all refer to the same thing. The terms are synonyms. mechanical - CORRECT ANSWER Solid State drives are not concerned with certain types of delays that plague conventional hard drives and optical drives. These delays are general grouped together under the term __________ delay. False - CORRECT ANSWER True or False: Every character you type on a *nix system always goes directly, with no intervention, to the process reading our input.

• CORRECT ANSWER If you are reading a memo that says it's a ''CERT Advisory'' what would it be talking about? True - CORRECT ANSWER True or False: DNS messages are sent via UDP. Apache - CORRECT ANSWER The most widely used web server on the Internet is: A. C. & D. - CORRECT ANSWER From the options below, select the most accurate statements concerning full and half duplex modes. (Select all that apply.) A. In full duplex mode, received characters must be echoed back to the display in order for the user to see them. B. Full duplex mode can be compared to traffic on a one-way street. C. In full duplex mode, any character typed in does not automatically appear on your screen unless the computer receiving it sends it back to the display. D. In half duplex mode, users see characters they type displayed twice. line buffering - CORRECT ANSWER Characters written to a stream are transmitted to the file in blocks when a newline or end of file character is encountered. I.e., a full line-at-a-time. This is known as __________. It runs because it uses dynamic linking libraries that link either at run time or at load time. [If at load time, then functions like printf are located and lined as the load module is loaded into memory. If at run time, then the first invocation of the function when the program runs causes the function to be found (either already in memory because another process is using it, or, if need be, loaded from the dynamic library) and linked to the process.] - CORRECT ANSWER The *nix command nm shows function names used in a program. Suppose you run nm on an executable file and discover that: "U _printf" - that is, the function printf() is undefined (the file does not contain code to implement this function). Yet, when you run the program, it runs perfectly well. How can this program run, if it still has undefined functions in it before being loaded into memory?

• Network ID:
• Broadcast Address: - CORRECT ANSWER IP addresses are 32-bit numbers. But not all of the possible values can be used by a host. Two specific addresses in every network are always reserved for special use. Identify / name these two reserved, pre-assigned, special use addresses and give a one-sentence description of why they are 'special' / what they are used for. True - CORRECT ANSWER True or False: A Bit Error Rate (BER) of 10^-19 is considered to be very bad. bit stuffing - CORRECT ANSWER In order to determine the beginning and the end of frames in a transmission, "magic bits" (01111110 in binary, 7E in hex or 126 in decimal) are inserted at the beginning and end of each frame. If a message contains six or more consecutive 1 bits, the sender inserts an extra 0 bit after five consecutive 1 bits in order to avoid confusion. This technique (inserting the extra 0 bit) is known as __________.
• HELO
• MAIL
• RCPT - CORRECT ANSWER Name three standard server commands: True - CORRECT ANSWER True or False: Voice over IP (VOIP) is interoperable with existing Public Switched Telephone Networks (PSTN).
• focus time delay
• layer change delay - CORRECT ANSWER Magnet and optical disk drives have two basic kinds of delay in common. Name these sources of delay: __________________ and __________________.

1. Compiler
2. Assembler
3. Linker
4. Loader - CORRECT ANSWER A program begins as source code, e.g., C++. In order for this source program to be run on a computer, it must be processed / translated by several programs. Indicate the correct chronological order of these processes / translations in which the programs that do this processing are run.

• Loader
• Assembler
• Compiler
• Linker

1. source code is translated to machine code
2. linker combines machine code with library object files
3. files are used to create a load module
4. load module "loads" files to memory - CORRECT ANSWER Number the following items to show the correct process of linking and loading a program.

• source code is translated to machine code
• linker combines machine code with library object files
• files are used to create a load module
• load module "loads" files to memory

1. Usability
2. Availability
3. Authentication
4. Authorization
5. Integrity
6. Confidentiality - CORRECT ANSWER Match the IT services below with the appropriate description. (No item should be used more than once).
7. IT resources provide the functionality intended.
8. Computing resources are accessible to authorized users when needed
9. Ensuring that users are really who they say they are. Confirmation of identity.
10. An IT service that assigns permissions to users. Giving individuals access to system objects based on their identity.
11. Nothing has been added, deleted, modified or altered in any way.
12. Information can only be seen by those individuals who are authorized to see it.