IT Questions and Answers :)

Friday, October 19, 2018

In Microsoft SQL Server, why does SELECT 1/2 return 0?

In Microsoft SQL Server, why does SELECT 1/2 return 0?

  • Numerator and denominator are both integers, so the result will be an integer
  • It doesn't - it returns 0.5
  • A bug in the code performing the division
  • A bug in the display in SSMS 

 
In Microsoft SQL Server, why does SELECT 1/2 return 0?

EXPLANATION

Due to the data type of the numerator and denominator being an "int", the return type is also assigned as an integer. While internally, the engine performs the calculation as 0.5, because the data type is an integer, the value gets converted to 0 and is returned as such.
Another way to say this is that the mathematical answer is 0.5 but because the system is only able to return an integer (whole number) the answer becomes 0 (the "whole number" in the answer).

Share:

Wednesday, October 17, 2018

Which of the following Windows console commands deletes a folder (c:\test), whether or not it is empty, without issuing any warnings?

Which of the following Windows console commands deletes a folder (c:\test), whether or not it is empty, without issuing any warnings?

  • rd test
  • rd test\* /q
  • del c:\test\*.* /s
  • rd c:\test /s /q 

Which of the following Windows console commands deletes a folder (c:\test), whether or not it is empty, without issuing any warnings?

EXPLANATION

The /s switch deletes ALL elements recursively inside the specified folder.
The /q switch is the silent mode, meaning there will be absolutely no warnings.
Caution

When you run rd /s in quiet mode, the entire directory tree is deleted without confirmation. Ensure that important files are moved or backed up before using the /q command-line option.
 
Share:

Thursday, October 11, 2018

What is the maximum number of devices that you can connect to a single USB 2.x controller?

What is the maximum number of devices that you can connect to a single USB 2.x controller?

  • 255
  • 31
  • 63
  • 127

What is the maximum number of devices that you can connect to a single USB 2.x controller?

EXPLANATION

Technically, a USB network is capable of supporting 128 nodes, though the USB controller itself is also a node.
In addition, any USB hubs, self-powered or bus-powered, count as additional nodes and reduce the number of nodes you can connect to the controller.
https://en.wikipedia.org/wiki/USB_hub#Physical_layout
 
Share:

Which of the following is NOT a daemon in Postfix?

Which of the following is NOT a daemon in Postfix?

  • qmgr
  • master
  •  crond
  • smtpd 

 
Which of the following is NOT a daemon in Postfix?

EXPLANATION

The crond daemon is a Linux daemon, not a Postfix daemon.
The master daemon is the brain of the Postfix mail system. It spawns all other daemons. The smtpd daemon (server) handles incoming connections. The qmgr daemon is the heart of the Postfix mail system. It processes and controls all messages in the mail queues.


Share:

Friday, September 28, 2018

At a Windows command prompt that is set to the root of the drive, which of the following commands will search the entire drive for all occurrences of the "Testing.docx" file?

At a Windows command prompt that is set to the root of the drive, which of the following commands will search the entire drive for all occurrences of the "Testing.docx" file?

  • DIR /ALL Testing.docx
  • DIR Testing.docx
  • DIR /S Testing.docx
  • DIR /R Testing.docx 

 
At a Windows command prompt that is set to the root of the drive, which of the following commands will search the entire drive for all occurrences of the "Testing.docx" file?

EXPLANATION

The directory command allows many flags, including the recursive search flag "/S".
This flag searches the current folder and all sub folders.
Share:

Thursday, September 27, 2018

What IEEE standard was Wired Equivalent Privacy first introduced?

What IEEE standard was Wired Equivalent Privacy first introduced?

  • 802.1x
  • 801.1a
  • 802
  • 802.11 


EXPLANATION

IEEE introduced WEP in the 802.11 standard but updated it in the 802.1x.

SOURCE

https://www.giac.org/paper/gsec/4214/wireless-security-ieee-80211-standards/106760
Share:

Wednesday, September 26, 2018

An initialization vector should be which of the following?

An initialization vector should be which of the following?

  • Repeatable and random
  • Unique and predictable
  • Unique and unpredicatable
  • Repeatable and unique 

 
An initialization vector should be which of the following?

EXPLANATION

An initialization vector (IV) should be unique and unpredictable. To prevent an attack,
an IV must not be repeated with a given key and should appear random.

SOURCE

https://en.wikipedia.org/wiki/Initialization_vector
Share:

Tuesday, September 25, 2018

Which type of RAID configuration requires minimum six drives?

Which type of RAID configuration requires minimum six drives?

  • RAID 50 (RAID 5 + 0)
  • RAID 100 (RAID 10+0)
  • RAID 6
  • RAID 60 (RAID 6 + 0) 

 
Which type of RAID configuration requires minimum six drives?

EXPLANATION

RAID 50, also called RAID 5+0, combines the straight block-level striping of RAID 0 with the distributed parity of RAID 5.[3] As a RAID 0 array striped across RAID 5 elements, minimal RAID 50 configuration requires six drives.

SOURCE

https://en.wikipedia.org/wiki/Nested_RAID_levels
Share:

In sql, which of the following is applicable to the CHAR datatype?

In sql, which of the following is applicable to the CHAR datatype?

  • CHAR stores alphanumeric characters of fixed size
  • Stores alphanumeric characters of variable length
  • to create scripts containing infinite characters
  • Type as many characters as you want 

 
In sql, which of the following is applicable to the CHAR datatype?

EXPLANATION

The only difference between CHAR and VARCHAR2 is that CHAR stores fixed-length alphanumeric characters, between 1 and 2000 bytes or characters. If you are stored in the JUNIOR surname in a CHAR (50) column, a column will contain a JUNIOR string + 44 whitespaces that are automatically added to the total column volume.

SOURCE

http://www.fabioprado.net/2011/08/qual-tipo-de-dado-devo-usar-char.html

Share:

Which of the following is NOT a computer programming language?

Which of the following is NOT a computer programming language?

  • Lisp
  • Occam
  • SNOBOL
  • Modal


EXPLANATION

MODAL isn't a programming language but is used in computer applications, especially within websites. It is a graphical window control element, subordinate to an application's main window.
SNOBOL (StriNg Oriented and symBOlic Language), is a text-string-oriented language developed by AT&T Bell Labs in the 1960s.
LISP, developed in the 1950s, is one of the oldest high-level programming languages and is only pre-dated by the likes of FORTRAN.
OCCAM was one of the earliest Concurrent programming languages, developed by INMOS as the native programming language for their Transputer Microprocessors.

SOURCE

https://en.wikipedia.org/wiki/List_of_programming_languages
 
Share:

Friday, September 21, 2018

Access management is most affected by which of these aspects of cloud computing?

Access management is most affected by which of these aspects of cloud computing?

  • Internet Service Provider
  • Virtualization
  • Federated Identity
  • Cloud backup 

 
Access management is most affected by which of these aspects of cloud computing?

EXPLANATION

Federated Identity allows you to use a central identity store both inside and outside of your organization. Cloud backup and Internet Service Provider have to do with IT service continuity management, not access management. Virtualization affects all IT processes, but not as much as identity federation.
Share:

Tuesday, September 18, 2018

Which of the following events would you NOT expect to see in the Windows security log?

Which of the following events would you NOT expect to see in the Windows security log?

  • Successful login attempts
  • User account deleted
  • Hardware driver failures
  • Shutdown events 

 
Which of the following events would you NOT expect to see in the Windows security log?

EXPLANATION

All of the above events will be logged in the Windows event log, however there are several different types of log that each contain relevant information.
Application log - contains logging information of events generated by applications.
Security log - contains information related to logon attempts, password changes, group membership, etc.
System log - contains information related to Windows system components, such as driver failures. These logs are predetermined by Windows.
Setup log - contains events related to application setup
ForwardedEvents log - used to store events collected from remote computers

The above alerts appear in the Windows security log as:
Event ID 4624 -  An account was successfully logged on
Event ID 4609 - Windows is shutting down
Event ID 4726 - User account was deleted
Hardware driver failures will appear in the system log




SOURCE

https://technet.microsoft.com/en-us/library/cc722404(v=ws.11).aspx
Share:

Monday, September 17, 2018

Which layer of the OSI model does a packet exist on?

Which layer of the OSI model does a packet exist on?

  • 3
  • 1
  • 2
Which layer of the OSI model does a packet exist on?

 

EXPLANATION

Packets exist on the third, or Network, layer of the OSI model. The following are the counterparts for packets on the other layers: Layer 1 (Physical): bits; Layer 2 (Data Link): frames; Layer 4 (Transport): segments.

SOURCE

https://en.wikipedia.org/wiki/OSI_model#Description_of_OSI_layers
Share:

Friday, September 14, 2018

To send someone a secure e-mail message using PGP, you should use which of the following?

To send someone a secure e-mail message using PGP, you should use which of the following?

  • The recipient's private key
  • Your public key
  • Your private key
  • The recipient's public key 

To send someone a secure e-mail message using PGP, you should use which of the following?

EXPLANATION

Pretty good privacy (PGP) can be used to send messages confidentially. For this, PGP combines symmetric-key encryption and public-key encryption. The message is encrypted using a symmetric
encryption algorithm, which requires a symmetric key. Each symmetric key is used only once and is also called a session key. The message and its session key are sent to the receiver. The session key must be sent to the receiver so they know how to decrypt the message, but to protect it during transmission, it is encrypted with the receiver's public key. Only the private key belonging to the receiver can decrypt the session key.
https://en.wikipedia.org/wiki/Pretty_Good_Privacy
Share:

Wednesday, September 12, 2018

In SQL, which of the following is the generally preferred way to handle the case where a transaction in progress terminates abnormally?

In SQL, which of the following is the generally preferred way to handle the case where a transaction in progress terminates abnormally?

  • Rollforward
  • Rollback
  • Switch to duplicate database
  • Reprocess transactions 

 
In SQL, which of the following is the generally preferred way to handle the case where a transaction in progress terminates abnormally?

EXPLANATION

A transaction is a logical unit of work that contains one or more SQL statements. A transaction is an atomic unit. The effects of all the SQL statements in a transaction can be either all committed (which means that they applied to the database) or all 
rolled back (undone from the database). So, if a transaction terminates abnormally, perform a rollback.

Share:

Tuesday, September 11, 2018

What VMware vSphere feature allows guest VMs to restart on another host in the event that their host fails?

What VMware vSphere feature allows guest VMs to restart on another host in the event that their host fails?

  • DRS
  • High availability
  • Storage DRS
  • Fault tolerance 

 
What VMware vSphere feature allows guest VMs to restart on another host in the event that their host fails?

EXPLANATION

VMware's High Availability (known to us lazy people as HA) allows guest VMs to restart on another host in the event of host failure. For example, if you have two hosts, both with VMs, and the first host has a hardware failure and becomes unresponsive, the VMs that were running on the failed host restart on the other host (provided it has the capacity to run them).
Read more here: https://www.vmware.com/products/vsphere/features/high-availability

Share:

Thursday, September 6, 2018

Which of the following is NOT a Linux distro?

Which of the following is NOT a Linux distro?

  • BSD
  • Ubuntu
  • Mint
  • Red Hat 

Which of the following is NOT a Linux distro?

EXPLANATION

Berkeley Software Distribution (BSD) is a Unix operating system derivative developed and distributed by the Computer Systems Research Group 
(CSRG) of the University of California, Berkeley, from 1977 to 1995. Today the term "BSD" is often used non-specifically to refer to any of the BSD descendants which together form a branch of the family ofUnix-like operating systems. Operating systems derived from the original BSD code remain actively developed and widely used.
Share:

Wednesday, September 5, 2018

By default, what is the lowest permission needed to join computers to an Active Directory domain?

By default, what is the lowest permission needed to join computers to an Active Directory domain?

  • Schema Admin
  • Domain Admins
  • Authenticated Users
  • Enterprise Admins 

 

EXPLANATION

By default any Authenticated User can add up to 10 computers to a domain.  The risk with this could be that a user sets up a new workstation and give themselves an admin account on the computer, then add it to the domain using their domain account. 
With these elevated permissions they could do many things.  Most notably, but not limited to, the higher chance of getting a virus on the system to an inexperienced user.

SOURCE

https://technet.microsoft.com/en-us/library/cc976452.aspx
Share:

Tuesday, September 4, 2018

In Unix systems, what are semaphores?

In Unix systems, what are semaphores?

  • A technique for pipeline deletion inside processes
  • A technique for coordinating or synchronizing activities
  • A technique for pipeline creation inside threads
  • A technique for Traffic lights management inside an operating system 

 
In Unix systems, what are semaphores?

EXPLANATION

In programming, especially in Unix systems, semaphores are a technique for coordinating or synchronizing activities in which multiple processes compete for the same operating system resources.
A semaphore is a value in a designated place in operating system (or kernel) storage that each process can check and then change. Depending on the value that is found, the process can use the resource or will find that it is already in use and must wait for some period before trying again. Semaphores can be binary (0 or 1) or can have additional values. Typically, a process using semaphores checks the value and then, if it using the resource, changes the value to reflect this so that subsequent semaphore users will know to wait.
Semaphores are commonly use for two purposes: to share a common memory space and to share access to files. Semaphores are one of the techniques for interprocess communication (IPC). The C programming language provides a set of interfaces or "functions" for managing semaphores.

SOURCE

https://whatis.techtarget.com/definition/semaphore
Share:

Monday, September 3, 2018

With regards to DNS, what is the difference between an A record and an AAAA record?

With regards to DNS, what is the difference between an A record and an AAAA record?

  • A record holds one IP for one host and AAAA record can hold up to four IPs for one host
  • A record replies to one ping and AAAA record replies to four pings.
  • A record is for the A-team and AAAA record is for a squad of A-teams.
  • A record holds the IPv4 address and AAAA record holds the IPv6 address 

With regards to DNS, what is the difference between an A record and an AAAA record?

EXPLANATION

An A and AAAA record are both primary DNS records.  They associate a host name with a specific IP address, so that when a user types in a web address, their browser knows where to go for the actual website. An A record holds the IPv4 address and an AAAA record holds the IPv6 address.
More info here - https://en.wikipedia.org/wiki/List_of_DNS_record_types
Share:

Friday, August 31, 2018

What of the following names is a USB device that registers itself as a network adapter but is a covert systems administration and penetration testing tool?

What of the following names is a USB device that registers itself as a network adapter but is a covert systems administration and penetration testing tool?

  • NET Ninja
  • BeamGun
  • Rubber Ducky
  • LAN Turtle 

What of the following names is a USB device that registers itself as a network adapter but is a covert systems administration and penetration testing tool?

EXPLANATION

The LAN Turtle is a covert Systems Administration and Penetration Testing tool providing stealth remote access, network intelligence gathering, and man-in-the-middle monitoring capabilities.
Housed within a generic "USB Ethernet Adapter" case, the LAN Turtle’s covert appearance allows it to blend into many IT environments.
See: https://lanturtle.com/ for more information
Share:

Thursday, August 30, 2018

You only want to use on-premises servers to authenticate. You would like to allow access to cloud email accounts through a user's local credentials. Which solution should you use?

You only want to use on-premises servers to authenticate. You would like to allow access to cloud email accounts through a user's local credentials. Which solution should you use?

  • Implement SaaS
  • Recreate user accounts in the cloud
  • Replicate local user accounts to the cloud
  • Identity federation 

You only want to use on-premises servers to authenticate. You would like to allow access to cloud email accounts through a user's local credentials. Which solution should you use?

EXPLANATION

Identity federation uses a single identity provider to authorize user access to multiple software applications, including cloud email.
Replicating user accounts means you are NOT using the on-premises user identities as you require. SaaS provides end-user software services over the network and has nothing to do with authorization. Recreating user accounts in the cloud won't work because we need to use local user accounts for authentication.
Share:

Which of these is NOT a card bus type?

Which of these is NOT a card bus type?

  • SOX
  • ISA
  • AGP
  • PCI 

 
Which of these is NOT a card bus type?

EXPLANATION

CardBus is the trade name for an advanced PC Card specification. The technology is used primarily in notebook and portable computers and fits in a slot like a conventional PC card. ISA, AGP, and PCI are all card bus types.
SOX is a common abbreviation for the Sarbanes-Oxley Act, a US Federal law governing publicly traded companies.

 


Share:

Tuesday, August 28, 2018

Which function key is used to check for spelling in MS Office?

Which function key is used to check for spelling in MS Office?

  • Alt + F11
  • F5
  • Alt + F4
  • F7

Which function key is used to check for spelling in MS Office?

EXPLANATION




Function key assignments common to all Microsoft Office applications are: F7 to check spelling.



 In Microsoft PowerPoint, F5 starts the slide show.



 Alt+F11 calls the Visual Basic Editor



 Alt+F4 is used to quit the application.
 
Share:

Monday, August 27, 2018

Which of these is not a high level Linux package manager?

Which of these is not a high level Linux package manager?

  • aptitude
  • yum
  • zypper
  • linupdate

Which of these is not a high level Linux package manager?

EXPLANATION

linupdate is the false one here. The others are all legitimate Linux package managers. Even though these are package managers, they use lower level tools to actually install the packages, such as rpm or dpkg.
Overview: http://www.tecmint.com/linux-package-management/
RPM & DPKG reference: http://packman.linux.is/
 
Share:

Friday, August 24, 2018

Which provides a method for validating source of a message through cryptographic authentication ?

Which provides a method for validating source of a message through cryptographic authentication ?

  • DNS
  • SPF
  • DNSSEC
  • DKIM

Which provides a method for validating source of a message through cryptographic authentication ?

EXPLANATION

DKIM provides a method for validating a domain name identity that is associated with a message through cryptographic authentication.

SOURCE

http://www.dkim.org/
 
Share:

Thursday, August 23, 2018

Which of these commands could you use to view the status of the system's ports?

Which of these commands could you use to view the status of the system's ports?

  • netstat -o
  • netstat -a
  • netstat -y
  • netstat -p 

 
Which of these commands could you use to view the status of the system's ports?

EXPLANATION

You can use the netstat -a command to list the ports used by the system and whether they are open and listening.
Share:

You need to encrypt and compress your backups before replicating them off site. Which is best practice, compress then encrypt, or encrypt then compress?

You need to encrypt and compress your backups before replicating them off site. Which is best practice, compress then encrypt, or encrypt then compress?

  • Neither!
  • Doesn't matter!
  • Encrypt first!
  • Compress first! 

You need to encrypt and compress your backups before replicating them off site. Which is best practice, compress then encrypt, or encrypt then compress?

EXPLANATION

If you encrypt the data first, it will be randomized and unintelligible by your compression application which need to compress the data in a logical format.
Compressing then encrypting is the way to go.

SOURCE

https://stackoverflow.com/questions/4676095/when-compressing-and-encrypting-should-i-compress-first-or-encrypt-first
Share:

Tuesday, August 21, 2018

In Active Directory, what would a RSOP report tell you?

In Active Directory, what would a RSOP report tell you?

  • Remote System Operation Protocol
  • Random State Oscillation Period
  • Removal Strategy for Outside People
  • Resultant Set Of Policy 

In Active Directory, what would a RSOP report tell you?

EXPLANATION




 A Resultant Set of Policy (RSOP) is a report of all Group Policy settings within Active Directory that shows how those settings can affect a network, or how existing Group Policy Objects (GPOs) affect various combinations of users and computers when the local security policy is applied.
Share:

Which of the following is implemented exclusively as firmware?

Which of the following is implemented exclusively as firmware?

  • BIOS
  • Linux
  • Database
  • Wi-Fi 

 
Which of the following is implemented exclusively as firmware?

EXPLANATION

Firmware is software that is permanently programmed into a device's read-only memory. Basic Input/Output System (BIOS) is an example of firmware.
Share:

Friday, August 17, 2018

Which of the following RegEx character sets does the '\w' meta-character most closely represent in Perl-compatible Regular Expression implementations?

Which of the following RegEx character sets does the '\w' meta-character most closely represent in Perl-compatible Regular Expression implementations?

  • [a-zA-Z0-9_]
  • [a-zA-Z]
  • [a-zA-Z0-9]
  • [a-zA-Z_] 

 
Which of the following RegEx character sets does the '\w' meta-character most closely represent in Perl-compatible Regular Expression implementations?

EXPLANATION

The "word" meta-character \w in RegEx will match the full alpha-numeric range, basically the full alphabet as well as number characters, and includes underscores.

Note that it matches more alphabet characters than the standard a through z: pretty much any alphabet character, such as 'ñ', also match.

http://www.w3schools.com/jsref/jsref_regexp_wordchar.asp
Share:

Thursday, August 16, 2018

What is the primary difference between LED and an LCD monitor?

What is the primary difference between LED and an LCD monitor?

  • price
  • Backlighting source
  • Doesn't last as long as plasma displays
  • screen size 

 
What is the primary difference between LED and an LCD monitor?

EXPLANATION

LCD
LCD is the abbreviation of Liquid Crystal display. There are two layers of glass in this technology that are joined together with liquid crystals in between. These crystals help pass or block the light. However, crystals do not produce any light and it comes through fluorescent lamps (CCFL) situated at the back of the screen.
LED
The technology in LED TV’s is much the same with the difference being the source of light at the back of the screen. Whereas it is CCFL in the case of LCD, there is Light emitting Diodes (LED’s) in the case of LED TV’s.
http://www.differencebetween.com/difference-between-lcd-and-vs-led-monitor/
http://www.diffen.com/difference/LCD_TV_vs_LED_TV
Share:

Where does Cryptolocker execute from on a Windows OS?

Where does Cryptolocker execute from on a Windows OS?

  • Desktop
  • C:\Programfiles
  • C:\Windows\System32
  • C:\Users\*User*\AppData\Local 

Where does Cryptolocker execute from on a Windows OS?

EXPLANATION

Cryptolocker runs from App Data Local and starts locking each file from A to Z then works on mapped drives from A to Z.

SOURCE

https://malwaretips.com/blogs/remove-cryptolocker-virus/
Share:

Tuesday, August 14, 2018

What is the default port used by Postfix?

What is the default port used by Postfix?

  • 25
  • 45
  • 37
  • 20 

 
What is the default port used by Postfix?

EXPLANATION

Postfix is an open source mail transfer agent (MTA) that is used to route and deliver emails. Postfix is the alternate of widely
used Sendmail MTA. Postfix uses port number 25 (SMTP) by default.

Share:

Monday, August 13, 2018

What type of RAID is RAID 2?

What type of RAID is RAID 2?

  • Byte-level striping with dedicated parity.
  • A striped set from a series of mirrored drives.
  • Block-level striping with dedicated parity.
  • Bit-level striping with dedicated Hamming-code parity. 

EXPLANATION

RAID 2
RAID 2 consists of bit-level striping with dedicated Hamming-code parity. All disk spindle rotation is synchronized and data is striped such that each sequential bit is on a different drive. Hamming-code parity is calculated across corresponding bits and stored on at least one parity drive. This level is of historical significance only; although it was used on some early machines (for example, the Thinking Machines CM-2), as of 2014 it is not used by any commercially available system.
RAID 2

SOURCE

https://en.wikipedia.org/wiki/Standard_RAID_levels#RAID_2 
Share:

Friday, August 10, 2018

In Linux system, which command will print the output of log file in reverse ?

In Linux system, which command will print the output of log file in reverse ?

  • less
  • cat
  • tac
  • rcs 

 
In Linux system, which command will print the output of log file in reverse ?

EXPLANATION

Let's assume that we have a log file named "Letters" that contains: A B C D (in separate lines).
To view the content of the log file in Linux terminal, the command will be:
linux@machine:~$ sudo cat Letters
And we will get the output:
A
B
C
D

To view the content of the log file in reverse, the command will be:
linux@machine:~$ sudo tac Letters
And we will get the output:
D
C
B
A




SOURCE

https://www.tecmint.com/learn-linux-cat-command-and-tac-command/
Share:

Thursday, August 9, 2018

While working on an issue on a clients network you learn that you will be using the 1000BaseCX standard. What type of cable will you be using.

While working on an issue on a clients network you learn that you will be using the 1000BaseCX standard. What type of cable will you be using.

  • CoreXtended Fiber
  • Single-mode fiber
  • Multimode fiber
  • STP

While working on an issue on a clients network you learn that you will be using the 1000BaseCX standard. What type of cable will you be using.

EXPLANATION

The 1000BaseCX standard specifies Gigabit Ethernet over STP cabling.
  1. Multi-mode Fiber is incorrect because 1000BaseSX and 1000BaseLX specify Gigabit Ethernet over two types of Multi-mode fiber.
  2. Single-mode fiber is used with 100BaseFX standard.
  3. As far as CoreXtended Fiber, there anin't no such animal.

SOURCE

http://www.thenetworkencyclopedia.com/entry/1000basecx/
Share:

Which of the following retains the information it's storing when the system power is turned off?

Which of the following retains the information it's storing when the system power is turned off?

  • ROM
  • RAM
  • GPU
  • CPU 

 
Which of the following retains the information it's storing when the system power is turned off?

EXPLANATION

Read only memory (ROM) is nonvolatile, meaning that turning off the computer doesn't erase it. 

Read-only memory (ROM) is a type of non-volatile memory used in computers and other electronic devices. Data stored in ROM can only be modified slowly, with difficulty, or not at all, so it is mainly used to store firmware (software that is closely tied to specific hardware, and unlikely to need frequent updates) or application software in plug-in cartridges.
Strictly, read-only memory refers to memory that is hard-wired, such as diode matrix and the later mask ROM (MROM), which cannot be changed after manufacture. Although discrete circuits can be altered in principle, integrated circuits (ICs) cannot, and are useless if the data is bad or requires an update. That such memory can never be changed is a disadvantage in many applications, as bugs and security issues cannot be fixed, and new features cannot be added.
More recently, ROM has come to include memory that is read-only in normal operation, but can still be reprogrammed in some way. Erasable programmable read-only memory (EPROM) and electrically erasable programmable read-only memory (EEPROM) can be erased and re-programmed, but usually this can only be done at relatively slow speeds, may require special equipment to achieve, and is typically only possible a certain number of times

Share:

Friday, August 3, 2018

In Windows Active Directory, what is the default time interval that the Knowledge Consistency Checker (KCC) uses for incremental syncs to review and update the Active Directory replication topology?

In Windows Active Directory, what is the default time interval that the Knowledge Consistency Checker (KCC) uses for incremental syncs to review and update the Active Directory replication topology?

  • 48 hours
  • 15 minutes
  • 60 minutes
  • 5 minutes 

 

EXPLANATION




By default, the knowledge consistency checker (KCC) reviews and makes modifications to the Active Directory replication topology every 15 minutes. The KCC ensures propagation of data, either directly or transitively, by creating and deleting connection objects as needed. The KCC recognizes changes that occur in the environment and ensures that domain controllers are not orphaned in the replication topology.

For more information on the KCC, see: https://technet.microsoft.com/en-us/library/cc961781.aspx
Share:

Thursday, August 2, 2018

Which of the following types of attacks do hackers use to gain information from you without the use of a computer program?

Which of the following types of attacks do hackers use to gain information from you without the use of a computer program?

  • Social Engineering
  • Cross Site Scripting
  • ARP Poisoning
  • SQL Injection 

 
Which of the following types of attacks do hackers use to gain information from you without the use of a computer program?

EXPLANATION

Social engineering, in the context of information security, refers to psychological manipulation of people into performing actions or divulging confidential information. A type of confidence trick for the purpose of information gathering, fraud, or system access, it differs from a traditional "con" in that it is often one of many steps in a more complex fraud scheme.
The term "social engineering" as an act of psychological manipulation of a human, is also associated with the social sciences, but its usage has caught-on among computer and information security professionals.

SOURCE

https://en.wikipedia.org/wiki/Social_engineering_(security)
Share:

What can be used to protect you from receiving email messages with a forged sender address?

What can be used to protect you from receiving email messages with a forged sender address?

  • Digital ID
  • IMAP
  • Secure SMTP
  • SPF

What can be used to protect you from receiving email messages with a forged sender address?

EXPLANATION

Sender Policy Framework (SPF) is a simple email-validation system designed to detect email spoofing by providing a mechanism to allow receiving mail exchangers to check that incoming mail from a domain comes from a host authorized by that domain's administrators.[1] The list of authorized sending hosts for a domain is published in the Domain Name System (DNS) records for that domain in the form of a specially formatted TXT record. Email spam and phishing often use forged "from" addresses, so publishing and checking SPF records can be considered anti-spam techniques.
IETF publication RFC 7208 dated April 2014 defines Sender Policy Framework as "proposed standard".

SOURCE

https://en.wikipedia.org/wiki/Sender_Policy_Framework 
Share:

Tuesday, July 31, 2018

In Unix, which of the following commands could you use to find files with a .log extension in the /var directory?

In Unix, which of the following commands could you use to find files with a .log extension in the /var directory?

  • find /var -name "*.log"
  • mv "*.log"
  • ls -l *.log
  • find / | grep "*.log" 

 

EXPLANATION

The "find" command specifies the directory, "/var". The "-name" option tells the "find" command to show only files that have a ".log" extension.

SOURCE

https://quiz.techlanda.com/2017/11/in-unix-which-of-following-commands.html
Share:

Where is the iSCSI protocol typically used?

Where is the iSCSI protocol typically used?

  • File sharing
  •  SANs (Storage Area Networks)
  • Inter-site routing
  • Internal drive arrays 

 
Where is the iSCSI protocol typically used?

EXPLANATION

iSCSI (Internet Small Computer System Interface) works on top of TCP and allows SCSI
commands to be sent over a network to iSCSI storage devices. This allows for a low cost SAN infrastructure using standard network hardware.

Share:

Popular Posts

Blog Archive