IT Questions and Answers :)

Friday, July 9, 2021

If you enter the Linux command pwd, what happens?

 If you enter the Linux command pwd, what happens?

  • You display your current working directory.
  • You display a list of users logged into the system.
  • You interactively change your system password.
  • You send a file to the attached printer.               

If you enter the Linux command pwd, what happens?


EXPLANATION

The pwd is an acronym for print working directory. The pwd command is considered as one of the most frequently used commands on Linux, AIX, HP-UX, *BSD, and other UNIX like operating systems along with the ls, and cd commands.

https://www.cyberciti.biz/faq/pwd-linux-unix-command-examples/

SOURCE

https://www.cyberciti.biz/faq/pwd-linux-unix-command-examples/
Share:

Thursday, July 8, 2021

The traditional sector size for a HDD is 512 bytes. What is the first generation Advanced Format sector size?

The traditional sector size for a HDD is 512 bytes. What is the first generation Advanced Format sector size?

  • 4096 bytes
  • 1024 bytes
  • 2048 bytes
  • 8192 bytes         

The traditional sector size for a HDD is 512 bytes. What is the first generation Advanced Format sector size?

EXPLANATION

Advanced Format is a generic term pertaining to any disk sector format used to store data on magnetic disks in hard disk drives (HDDs) that exceeds 512 to 528 bytes per sector, such as the 4096-byte (4 KiB) sectors of the first-generation Advanced Format hard disk drives.      
Share:

Which connector supports high frequencies required for applications beyond 10 Gigabit Ethernet?

Which connector supports high frequencies required for applications beyond 10 Gigabit Ethernet?

  • RJ45
  • GG100
  • GG45
  • RJ11     

Which connector supports high frequencies required for applications beyond 10 Gigabit Ethernet?


EXPLANATION

The GG45 (where GG stands for GigaGate, and 45 is to denote the backward compatibility with the 8P8C modular connector – often colloquially called RJ45) is a connector for high-speed Category 7 cable (generally known as Cat 7) LAN cabling developed by Nexans.

The cabling system was standardized in 2001 as IEC 60603-7-7, and then selected as a worldwide Category 7 cabling standard within ISO-11801.

GG45 connectors provide backwards compatibility for standard 8P8C (8P8C) connectors in a Category 6 cable interface (mode 1), where eight conductors are used for Cat 6 (100/250 MHz) operation.

In addition, GG45 has four additional contacts (two in each extreme corner) that interface with new high-speed Cat 7 600 MHz and Cat 7a 1000 MHz networks. Two twisted pairs are connected to these additional contacts, while the other two twisted pairs remain connected to the original 8P8C connector's most distant pins: 1 and 2; and 7 and 8. A Category 6 or 6A plug uses the original contact positions, but a Category 7 or 7A plug instead uses the contacts located in the four corners and has a protrusion that activates a switch within the jack for the alternative contact positions. This reduces crosstalk within the connector that higher speed data is sensitive to. The key advantage is that the GG45 interface therefore has plenty of headroom, combined with the ability to migrate to higher speed service by upgrading to Category 7A patch cords that activate the switch in the jack.[1]


SOURCE

Share:

Monday, July 5, 2021

What is RFC 1918?

What is RFC 1918?

  • A standar for HTTP
  • An IRC channel for network admins
  • A standard for private IPv4 addresses
  • A random UDP port number               
What is RFC 1918?


EXPLANATION

Wikipedia entry: Addresses in the private space are not allocated to any specific organization and anyone may use these addresses without approval from a regional Internet registry. However, IP packets addressed from them cannot be transmitted through the public Internet, and so if such a private network needs to connect to the Internet, it must do so via a network address translator (NAT) gateway, or a proxy server.

IETF documentation for RFC 1918

IPv6 equivalent RFC 4193

Share:

Thursday, June 3, 2021

If you wanted to retrieve all the records from TableA and only those records from TableB that matched, which query would you use?

 If you wanted to retrieve all the records from TableA and only those records from TableB that matched, which query would you use?

  • SELECT TableA.*, TableB.* FROM TableA INNER JOIN TableB ON TableA.PK = TableB.FK
  • SELECT TableA.*, TableB.* FROM TableA RIGHT JOIN TableB ON TableA.PK = TableB.FK
  • SELECT TableA.*, TableB.* FROM TableA LEFT JOIN TableB ON TableA.PK = TableB.FK
  • SELECT * FROM TableA UNION ALL SELECT * FROM TableB         

If you wanted to retrieve all the records from TableA and only those records from TableB that matched, which query would you use?

EXPLANATION

In this question we are joining TableA to TableB

An INNER JOIN will give you the results where there is a match between TableA and TableB on the join criteria.

A LEFT JOIN will return every record from the table on the left (TableA in this case) and only those records from TableB where there is a match on the join criteria.

A RIGHT JOIN does the exact opposite of the LEFT JOIN. It will return every record from the table on the right (TableB in this case) and only those records from TableA where there is a match on the join criteria.

A UNION ALL statement takes the results of two or more queries and returns them as one dataset. The only caveat is that the columns being returned must match for all queries.

SOURCE

Share:

Which of the following is a non-volatile memory ?

Which of the following is a non-volatile memory ?

  • RAM
  • LSI
  • VLSI
  • ROM   
Which of the following is a non-volatile memory ?


EXPLANATION

ROM stands for Read-Only-Memory. This type of memory is static with regards to the storage in that the changes to the ROM are not allowed (in most cases). 


SOURCE

Share:

Monday, May 31, 2021

A DHCP assigned IP address has a lease duration of 6 days. After how many days does the client start to try to renew the address if it is not rebooted?

A DHCP assigned IP address has a lease duration of 6 days. After how many days does the client start to try to renew the address if it is not rebooted?

  • 4 days
  • 3 days
  • 5 days
  • 6 days        

A DHCP assigned IP address has a lease duration of 6 days. After how many days does the client start to try to renew the address if it is not rebooted?


EXPLANATION

After half the lease time is over, the client will start to try to renew and extend the current lease with the DHCP server he got the address from. If he is unsuccessful, he will try again when 87.5% of the lease time is up, trying to find any server that can renew and extend the lease. If no server is found, the client releases the address after the lease time is up and the administrator is in trouble...

More info here.       
Share:

Which of the following is the default port used for POP3 SSL Traffic?

 Which of the following is the default port used for POP3 SSL Traffic?

  • 995
  • 25
  • 587
  • 110
Which of the following is the default port used for POP3 SSL Traffic?


EXPLANATION

POP uses port 110, but SSL/TLS encrypted POP uses port 995.


SOURCE

Share:

What is it called when RAID appears to be hardware-based, but is actually software-based?

What is it called when RAID appears to be hardware-based, but is actually software-based?

  • FakeRAID
  • HS-RAID
  • FalseRAID
  • Triple Parity RAID          
What is it called when RAID appears to be hardware-based, but is actually software-based?


EXPLANATION

FakeRAID is the industry term for software RAID that appears to be hardware RAID. This type of RAID is common in desktops.

What is Fake RAID?

So-called Fake RAID is a name commonly applied to motherboard / BIOS RAID features that provide the bare minimum for RAID functionality as it is understood. Low-end RAID cards get lumped in to this category because they may not offer the same DRAM cache and power loss protection features found in their more expensive counterparts. Why do low end RAID cards exist? They are mostly used to boot multiple operating systems from one array of hard drives.

SOURCE

https://skrypuch.com/raid/


     
Share:

Friday, May 21, 2021

In the early days of the Internet and Microsoft Windows 3.11, what were two components that needed to be installed before Windows could access the Internet using TCP/IP?

In the early days of the Internet and Microsoft Windows 3.11, what were two components that needed to be installed before Windows could access the Internet using TCP/IP?

  • 4Gb of RAM and a solid state disk drive.
  • Win32s and Trumpet WinSock
  • 16-bit TCP/IP stack and Internet Explorer 4.
  • A lot of coffee and a new PC. 

In the early days of the Internet and Microsoft Windows 3.11, what were two components that needed to be installed before Windows could access the Internet using TCP/IP?


EXPLANATION

If you are installing the Windows 3.x 16-bit version of Netscape Navigator, it requires the Microsoft Win32s software be installed first.
If you received a copy of Win32s on a N.E.O.Net Sign-up Kit disk, then insert Win32s Disk 1 - Setup into your system's floppy drive, run the Setup application as outlined on the disk label, and follow the instructions on-screen.

Windows 3.x also requires that you have a dialer/winsock application such as Trumpet. You may wish to install Trumpet prior to Netscape.

With Windows 3.1/3.11 being a 16 bit operating system, the Win32s allowed certain 32-bit applications to run on the host system.

Trumpet Winsock would act as the modem/network "dialer" to make the connection to your ISP.

Internet Explorer 4 was not released until 1997 for use with Windows 95 or Windows NT 4.0, both of these OS's were 32 bit and did not require Win32s or Trumpet Winsock.

SOURCE

Share:

In Microsoft Remote Desktop Services, What is the correct command that should be executed before installing software onto a terminal server?

 In Microsoft Remote Desktop Services, What is the correct command that should be executed before installing software onto a terminal server?

  • change user /install
  • set mode /install
  • change /system install
  • Set-Mode "Install"        
In Microsoft Remote Desktop Services, What is the correct command that should be executed before installing software onto a terminal server?


EXPLANATION

To install an end-user application on an RD Session Host server, the RD Session Host server must first be switched into a special install mode called RD-Install to ensure that the application will be able to run in a multi-user environment. After your applications have been installed on your RD Session Host server, you must switch the server back into execution mode (RD-Execute) before users can remotely connect to your server. You can switch between the install and execute modes from the command line using these commands:
change user /install
change user /execute

SOURCE

https://technet.microsoft.com/en-us/library/ff432698.aspx
       
Share:

Wednesday, May 19, 2021

What graphical tool can create user and computer accounts and was redesigned for Windows Server 2012?

What graphical tool can create user and computer accounts and was redesigned for Windows Server 2012?

  • Active Directory Administrative Center
  • Elevated Command Prompt
  • PowerShell
  • Active Directory Computers and Users        
What graphical tool can create user and computer accounts and was redesigned for Windows Server 2012?


EXPLANATION

The Active Directory Administrative Center (ADAC) in Windows Server includes enhanced management experience features. These features ease the administrative burden for managing Active Directory Domain Services (AD DS). The following topics provide an introduction and additional details:

SOURCE

https://docs.microsoft.com/en-us/windows-server/identity/ad-ds/get-started/adac/active-directory-administrative-center

       
Share:

In Linux, what is the result of this command: tar -xvf public_html.tar

In Linux, what is the result of this command: tar -xvf public_html.tar

  • Untar or extract public_html.tar to /root
  • Untar or extract public_html.tar to /home/public_html
  • Untar or extract public_html.tar to the current directory
  • Create a new public_html.tar archive using the files in the current directory        
In Linux, what is the result of this command: tar -xvf public_html.tar

EXPLANATION

To untar or extract a tar file, just issue following command using option x (extract). For example the below command will untar the file public_html.tar in present working directory:

# tar -xvf public_html.tar

SOURCE

https://www.tecmint.com/18-tar-command-examples-in-linux/

       
Share:

Thursday, April 22, 2021

For an IBM i user profile, what authority could be considered "keys to the kingdom"?

 For an IBM i user profile, what authority could be considered "keys to the kingdom"?

  • *IOSYSCFG
  • *SECOFR
  • *ALLOBJ
  • *ALLAUT            
For an IBM i user profile, what authority could be considered "keys to the kingdom"?


EXPLANATION

*ALLOBJ authority on a user profile grants a user access to everything on the system. Although the profile may not have the ability to directly do system functions like hardware configuration or system saves, *ALLOBJ grants the profile access to objects that do have those privileges. *ALLOBJ authority is often granted to all profiles on a system to make up for poor security planning and is a dangerous practice.

SOURCE

https://www.itjungle.com/2017/04/24/state-ibm-security-seven-areas-demand-attention/
   
Share:

Tuesday, April 20, 2021

How many Kilobytes in 1 Gigabit?

 How many Kilobytes in 1 Gigabit?

  • 125000
  • 1000000
  • 100000
  • 122070     
          
How many Kilobytes in 1 Gigabit?

EXPLANATION

Bits and Bytes are different by a factor of 8.  A lot of times people mistaken these, which can lead to disastrous consequences when talking about IT contracts.  Make sure you dot your i's, cross your t's, and check your bits & bytes!!

SOURCE

https://bit-calculator.com/
Share:

Monday, April 19, 2021

What do Java and JavaScript have in common?

 What do Java and JavaScript have in common?

  • None of these
  • Both are compiled to bytecode
  • Both use prototypes
  • Both use JAR files               
What do Java and JavaScript have in common?

EXPLANATION

Java and JavaScript share very little in common, despite both using C-style syntax and misleading name similarity

SOURCE

https://en.wikipedia.org/wiki/Java_(programming_language)




Share:

In Unix/Linux, there is FSCK. What is its equivalent in Windows?

 In Unix/Linux, there is FSCK. What is its equivalent in Windows?

  • TRACERT
  • CHKDSK
  • FDISK
  • FSUTIL               
In Unix/Linux, there is FSCK. What is its equivalent in Windows?


EXPLANATION

The system utility fsck (file system consistency check) is a tool for checking the consistency of a file system in Unix and Unix-like operating systems, such as Linux, macOS, and FreeBSD. A similar command, CHKDSK exists in Microsoft Windows.

SOURCE

https://en.wikipedia.org/wiki/Fsck

Share:

Tuesday, April 13, 2021

In Linux, what is the result of this command: tar -xvf public_html.tar

In Linux, what is the result of this command: tar -xvf public_html.tar

  • Untar or extract public_html.tar to /home/public_html
  • Create a new public_html.tar archive using the files in the current directory
  • Untar or extract public_html.tar to the current directory
  • Untar or extract public_html.tar to /root             

In Linux, what is the result of this command: tar -xvf public_html.tar


EXPLANATION

To untar or extract a tar file, just issue following command using option x (extract). For example the below command will untar the file public_html.tar in present working directory:

# tar -xvf public_html.tar

SOURCE

Share:

Monday, April 12, 2021

What is the minimum Domain Functional Level required to use DFSR to replicate SYSVOL?

 What is the minimum Domain Functional Level required to use DFSR to replicate SYSVOL?

  • Windows Server 2008 R2
  • Windows Server 2012
  • Windows Server 2003
  • Windows Server 2008
What is the minimum Domain Functional Level required to use DFSR to replicate SYSVOL?

EXPLANATION

The domain functional level needed to be Windows server 2008 to support DFS Replication of SYSVOL. 

SOURCE

https://techcommunity.microsoft.com/t5/storage-at-microsoft/streamlined-migration-of-frs-to-dfsr-sysvol/ba-p/425405
               
Share:

Friday, April 9, 2021

A security analyst received a compromised workstation. Its hard drive may contain evidence of criminal activities. Which of the following is the FIRST thing the analyst must do to ensure the integrity of the hard drive while performing the analysis?

 A security analyst received a compromised workstation. Its hard drive may contain evidence of criminal activities. Which of the following is the FIRST thing the analyst must do to ensure the integrity of the hard drive while performing the analysis?

  • Use write blockers.
  • Make a copy of the hard drive.
  • Install it on a different machine and explore the content.
  • Run rm R command to create a hash.         
A security analyst received a compromised workstation. Its hard drive may contain evidence of criminal activities. Which of the following is the FIRST thing the analyst must do to ensure the integrity of the hard drive while performing the analysis?

EXPLANATION

If you try to make a copy of the disk without the write blockers, you run risk of adding more data than already is into the hard drive. 

SOURCE

https://comptiaexamtest.com/CySA+CS0-001/comptia-cysa-cs0-001-question010/
      
Share:

Popular Posts