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 

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 

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 :

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 

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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What backup type would generally provide the fastest backup times

What backup type would generally provide the fastest backup times

• Incremental
• Full
• Differential
• Archival 

EXPLANATION

 Full backups copy all sectors of the file image whether the sectors contain data or not. This is easy to operate; however, it is time-consuming, space-intensive, and the least flexible method.

An incremental backup is one in which successive copies of the data contain only that portion that has changed since the preceding backup copy was made. When a full recovery is needed, the restoration process would need the last full backup plus all the incremental backups until the point of restoration. Incremental backups are often desirable as they reduce storage space usage, and are quicker to perform than differential backups.

 A differential backup is a type of data backup that preserves data, saving only the difference in the data since the last full backup.

 Archival backup is a type of data backup in which all files are copied to a backup storage device. Archival backups are also called full backup.Contrast with incremental backups, in which only modified files are copied.

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[blank] is a set of voluntary standards governing encryption.

[blank] is a set of voluntary standards governing encryption.

• PKCS
• ISA
• RSA
• PKI 

EXPLANATION

 In cryptography, PKCS stands for "Public Key Cryptography Standards". These are a group of public-key cryptography standards devised and published by RSA Security Inc, starting in the early 1990s

SOURCE

https://quizlet.com/57845307/sec-preface-flash-cards/

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Which of the following values is associated with the Passwordless Guest Account on Ubuntu?

Which of the following values is associated with the Passwordless Guest Account on Ubuntu?

• U6aMy0wojraho
• [NULL]
• [NULL=guestsession]
• $1EgYb2Fn6I$2EgYv4xZTUtb2Fn6I 

EXPLANATION

The default user on the Ubuntu Live CD is configured to not require a password. By replacing the password value of your guest user with the one from the Ubuntu Live CD, users will be able to log in by leaving the password prompt blank.

To begin, create a new user to serve as your guest account. You will be required to enter a password. Enter anything you like, as you will be changing the password shortly. Be sure to revoke any privileges (such as Administering the system) that you do not want your guests to have.

Once the new account is created, open a terminal and enter the appropriate command for your version of Ubuntu:

Ubuntu

gksudo gedit /etc/shadow

Kubuntu

kdesu kate /etc/shadow

Xubuntu

gksudo mousepad /etc/shadow

You will be prompted to enter your password (not the one for the account you are creating). After that is complete, a text editor will display the contents of the /etc/shadow file. You will need to locate the line which contains information for your guest account. The line will appear similar to this:

guest:$1$2EgYb2Fn6I$2EgYv4xZTUtb2Fn6I$2E.gYdgo8dq9EgYv:13720:1:99999:7:::

Once you locate the line for your guest account, you need to replace the text between the second and third colons. Erase the current value, and enter the following in its place:

U6aMy0wojraho

If your line began like the above example, it would now look like this:

guest:U6aMy0wojraho:13720:1:99999:7:::

Save the file and exit from the text editor. Once this is complete, you will be able to log in to your guest account from the login screen. When you select the account, you will be prompted for a password, but will be allowed to log in if you leave the space blank.

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What is the name of the protocol behind PowerShell's Remoting feature, which is Microsoft's new standard for administrative communications?

What is the name of the protocol behind PowerShell's Remoting feature, which is Microsoft's new standard for administrative communications?

• RPC
• WMI
• WS-MAN
• WS-AT 

EXPLANATION

The Connect-WSMan cmdlet connects to the WinRM service on a remote computer, and it establishes a persistent connection to the remote computer. You can use this cmdlet in the context of the WSMan provider to connect to the WinRM service on a remote computer. However, you can also use this cmdlet to connect to the WinRM service on a remote computer before you change to the WSMan provider. The remote computer appears in the root directory of the WSMan provider.
Explicit credentials are required when the client and server computers are in different domains or workgroups.
For information about how to disconnect from the WinRM service on a remote computer, see the Disconnect-WSMan cmdlet.

Examples

Example 1: Connect to a remote computer

PowerShell

PS C:\> Connect-WSMan -ComputerName "server01"
PS C:\> cd wsman:
PS WSMan:\>
PS WSMan:\> dir
WSManConfig: Microsoft.WSMan.Management\WSMan::WSMan

ComputerName                                  Type
------------                                  ----
localhost                                     Container
server01                                      Container

This command creates a connection to the remote server01 computer.
The Connect-WSMan cmdlet is generally used in the context of the WSMan provider to connect to a remote computer, in this case the server01 computer. However, you can use the cmdlet to establish connections to remote computers before you change to the WSMan provider. Those connections appear in the ComputerName list.

 

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