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Wednesday, April 17, 2019

What technology is not used to implement confidentiality?

What technology is not used to implement confidentiality?

  • Access Controls
  • Authentication
  • Auditing
  • Encryption 

What technology is not used to implement confidentiality?

EXPLANATION

What technology is not used to implement confidentiality, but is used verify that an administrator is not accessing data that he should not be accessing? Auditing

SOURCE

https://quizlet.com/111340244/understanding-security-layers-lesson-1-flash-cards/

 

 


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Which one is NOT one of the 4 layers of the TCP/IP model

Which one is NOT one of the 4 layers of the TCP/IP model

  • Data
  • Internet
  • Application
  • Network access


Which one is NOT one of the 4 layers of the TCP/IP model

 EXPLANATION

Layer 4. Application Layer

Application layer is the top most layer of four layer TCP/IP model. Application layer is present on the top of the Transport layer. Application layer defines TCP/IP application protocols and how host programs interface with Transport layer services to use the network.
Application layer includes all the higher-level protocols like DNS (Domain Naming System), HTTP (Hypertext Transfer Protocol), Telnet, SSH, FTP (File Transfer Protocol), TFTP (Trivial File Transfer Protocol), SNMP (Simple Network Management Protocol), SMTP (Simple Mail Transfer Protocol) , DHCP (Dynamic Host Configuration Protocol), X Windows, RDP (Remote Desktop Protocol) etc.


Layer 3. Transport Layer

Transport Layer is the third layer of the four layer TCP/IP model. The position of the Transport layer is between Application layer and Internet layer. The purpose of Transport layer is to permit devices on the source and destination hosts to carry on a conversation. Transport layer defines the level of service and status of the connection used when transporting data.
The main protocols included at Transport layer are TCP (Transmission Control Protocol) and UDP (User Datagram Protocol).

Layer 2. Internet Layer

Internet Layer is the second layer of the four layer TCP/IP model. The position of Internet layer is between Network Access Layer and Transport layer. Internet layer pack data into data packets known as IP datagrams, which contain source and destination address (logical address or IP address) information that is used to forward the datagrams between hosts and across networks. The Internet layer is also responsible for routing of IP datagrams.
Packet switching network depends upon a connectionless internetwork layer. This layer is known as Internet layer. Its job is to allow hosts to insert packets into any network and have them to deliver independently to the destination. At the destination side data packets may appear in a different order than they were sent. It is the job of the higher layers to rearrange them in order to deliver them to proper network applications operating at the Application layer.
The main protocols included at Internet layer are IP (Internet Protocol), ICMP (Internet Control Message Protocol), ARP (Address Resolution Protocol), RARP (Reverse Address Resolution Protocol) and IGMP (Internet Group Management Protocol).

Layer 1. Network Access Layer

Network Access Layer is the first layer of the four layer TCP/IP model. Network Access Layer defines details of how data is physically sent through the network, including how bits are electrically or optically signaled by hardware devices that interface directly with a network medium, such as coaxial cable, optical fiber, or twisted pair copper wire.
The protocols included in Network Access Layer are Ethernet, Token Ring, FDDI, X.25, Frame Relay etc.
The most popular LAN architecture among those listed above is Ethernet. Ethernet uses an Access Method called CSMA/CD (Carrier Sense Multiple Access/Collision Detection) to access the media, when Ethernet operates in a shared media. An Access Method determines how a host will place data on the medium.
IN CSMA/CD Access Method, every host has equal access to the medium and can place data on the wire when the wire is free from network traffic. When a host wants to place data on the wire, it will check the wire to find whether another host is already using the medium. If there is traffic already in the medium, the host will wait and if there is no traffic, it will place the data in the medium. But, if two systems place data on the medium at the same instance, they will collide with each other, destroying the data. If the data is destroyed during transmission, the data will need to be retransmitted. After collision, each host will wait for a small interval of time and again the data will be retransmitted.

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What does the acronym GNU stand for?

What does the acronym GNU stand for?

  • Guaranteed Not Unix
  • GNU's Not Unix
  • Genuine Non-Unix
  • Gratis Not Unix 

What does the acronym GNU stand for?

EXPLANATION

In computing, an early tradition in the hacker community (especially at MIT) was to choose acronyms and abbreviations that referred humorously to themselves or to other abbreviations. Perhaps the earliest example in this context – from 1960 – is the backronym "Mash Until No Good", which was created to describe Mung, and a while later was revised to "Mung Until No Good". It lived on as a recursive command in the editing language TECO.[3] In 1977 or 1978 came TINT ("TINT Is Not TECO"), an editor for MagicSix written (and named) by Ted Anderson. This inspired the two MIT Lisp Machine editors called EINE ("EINE Is Not Emacs", German for one) and ZWEI ("ZWEI Was EINE Initially", German for two). These were followed by Richard Stallman's GNU (GNU's Not Unix).
Many others also include negatives, such as denials that the thing defined is or resembles something else (which the thing defined does in fact resemble or is even derived from), to indicate that, despite the similarities, it was distinct from the program on which it was based.[3]
An earlier example appears in a 1976 textbook on data structures, in which the pseudo-language SPARKS is used to define the algorithms discussed in the text. "SPARKS" is claimed to be a non-acronymic name, but "several cute ideas have been suggested" as expansions of the name. One of the suggestions is "Smart Programmers Are Required to Know SPARKS".[4] (this example is tail recursive)

SOURCE

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

 

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The password management system found in MacOS is known as...

The password management system found in MacOS is known as...

  • Keychain
  • Key Ring
  • Key Fob
  • Key Grip 
 


EXPLANATION

Keychains were originally developed in the early 1990s for use with an Apple email system called PowerTalk. The idea was that PowerTalk could communicate with many mail servers and online services, so it would use a keychain file to hold user authentication information within the application to automatically and securely log the user into the variety of services. With the creation and release of Mac OS X in the early 2000s, Keychain became part of the operating system and was used to hold much more information.
 a secure database of a users passwords
-2 default chains: System and System Roots (belong to the OS)
-use Keychain Access utility to create multiple keychains







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In Linux "cat" is the command used to

In Linux "cat" is the command used to

  • Come out of shell
  • Move directory
  • See the contents of file
  • Come out of shell 
In Linux "cat" is the command used to

EXPLANATION

The cat (short for "concatenate") command is one of the most frequently used command in Linux/Unix like operating systems.cat command allows us to create single or multiple files, view contain of file, concatenate files and redirect output in terminal or files.

The cat command in Linux allows you to concatenate files and display the output to the standard output; in most cases this is a screen. One of the most common uses of cat is to display a file to the screen and also to create a file on the fly and allow basic editing straight at the terminal .
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Which one is a Default root bridge for STP (Spanning tree protocol) ?

Which one is a Default root bridge for STP (Spanning tree protocol) ?

  • 32768
  • 65536
  • 57344
  • 36864 

Which one is a Default root bridge for STP (Spanning tree protocol) ?


The bridge priority is a customizable value that you can use to influence which switch becomes the root bridge. The switch with the lowest priority, which means lowest BID, becomes the root bridge (the lower the priority value, the higher the priority). The default value for the priority of all Cisco switches is 32768. The priority range is between 1 and 65536; therefore, 1 is the highest priority.


Now have a look at this diagram :
stp.bmp

The early implementation of STP was designed for networks that did not use VLANs. There was a single common spanning tree across all switches. When VLANs started became common for network infrastructure segmentation, STP was enhanced to include support for VLANs. As a result, the extended system ID field contains the ID of the VLAN with which the BPDU is associated.



When the extended system ID is used, it changes the number of bits available for the bridge priority value, so the increment for the bridge priority value changes from 1 to 4096. Therefore, bridge priority values can only be multiples of 4096.


Note that 2 raise to power 12 is 4096. Now if you occupy even a single bit ( out of the 4 bits) for the Bridge Priority,

It means 4096*2=8192 (multiple of 4096..)


The extended system ID value is added to the bridge priority value in the BID to identify the priority and VLAN of the BPDU frame.

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What is a best execution command (cmd.exe) to get PC serial number ?

What is a best execution command (cmd.exe) to get PC serial number ?

  • wmic bios serialnumber
  • wmic bios get serialnumber
  • -wmic bios get serial
  • wmic bios get serial number 

What is a best execution command (cmd.exe) to get PC serial number ?

EXPLANATION

We can find other bios information also using ‘wmic bios get’ command. In the above command you need to replace ‘serialnumber‘ with the appropriate property of bios. Use the below command to get the list of properties.

SOURCE

https://www.windows-commandline.com/wmic-bios-get-serial-number/

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