Misc

Question 1

Where are alert mail messages stored on red hat based systems?

Answer 1

/var/spool/mail/>user<

*file

Question 2

What is the command to change user password expiry information?

Answer 2

chage

Question 3

What are some desktop environments?

Answer 3

Gnome - built on gtk+ toolkit
KDE - built on qt toolkit
XFCE - built on gtk+ toolkit

Question 4

How do you switch from a graphical to terminal environment?

Answer 4

Ctrl + Alt + FN
i.e Ctrl + Alt + F2
Alt + F1 return back to desktop

Question 5

How do you switch between terminal environments?

Answer 5

Alt + FN

i.e Alt + F3

Question 6

What is the configuration file location for all man pages?

Answer 6

/etc/man_db.conf

Question 7

What are all of the man page sections?

Answer 7

1
2
3

Question 8

What kind of distribution does Apple macOS use?

Answer 8

Apple’s macOS is a fully-qualified UNIX distribution based on BSD Unix (an operating system distributed until 1995), complemented by a large amount of proprietary code. I

t runs on hardware specifically optimized to work with Apple software. Linux can be any one of hundreds of distribution packages designed or optimized for whatever task is required. Only Microsoft Windows is based on a proprietary code base that isn’t either UNIX- or Linux-based.

Question 9

Operating systems and software upgrades come on a periodic basis what are they called?

Answer 9

Operating systems and software upgrades come on a periodic basis, called a release cycle.

The release cycle dictates how often software is upgraded

Question 10

What is a maintenance cycle?

Answer 10

Vendors only support older versions of software for a certain period of time before not offering any updates; this is called a maintenance cycle or life cycle.

Question 11

What is a linux distribution comprised of?

Answer 11

A Linux distribution is a bundle of software, typically comprised of the Linux kernel, utilities, management tools, and even some application software in a package which also includes the means to update core software and install additional applications.

Question 12

What are development packages?

Answer 12

Additionally, there are development packages where users can contribute code and submit patches for possible inclusion into new releases.

Question 13

List three linux enterprise distributions?

Answer 13

Enterprise distributions are fewer by far, being offered mainly by Red Hat, Canonical and SUSE.

Question 14

What is Fedora?

Answer 14

Fedora is often considered the community-oriented beta release of RedHat. Features are added and changed in the Fedora release before finding their way into the enterprise-ready RedHat distribution.

Question 15

What is SLES?

Answer 15

SLES (SUSE Linux Enterprise Server)

Question 16

Debian Linux releases?

Answer 16

Ubuntu

Linux Mint

Question 17

Slackware Linux releases?

Answer 17

SLS
Slackware
S.U.S.E.  (derived from slackware)
SuSE ---> SLES
SUSE
openSUSE

Question 18

Red Hat Linux releases?

Answer 18

Red Hat
Red Hat Enterprise -->
Scientific Linux
CentOS
Fedora Core
Fedora

Question 19

Which version of SUSE is free?

Answer 19

openSUSE

Question 20

What file format is Debians management system based on?

Answer 20

Debian came up with its own package management system based on the .deb file format. While Red Hat leaves non-Intel and AMD platform support to derivative projects, Debian supports many of these platforms directly.

Question 21

Why do some people use the term GNU/Linux instead of Linux alone?

Answer 21

Linux is a kernel, and many of the commands covered in this course are actually part of the GNU package. That is why some people insist on using the term GNU/Linux instead of Linux alone.

Question 22

What is the world’s most popular Linux distribution?

Answer 22

Android, sponsored by Google, is the world’s most popular Linux distribution. It is fundamentally different from its counterparts.

Android uses the Dalvik virtual machine with Linux, providing a robust platform for mobile devices such as phones and tablets. However, lacking the traditional packages that are often distributed with Linux (such as GNU and Xorg), Android is generally incompatible with desktop Linux distributions.

This incompatibility means that a Red Hat or Ubuntu user cannot download software from the Google Play store. Likewise, a terminal emulator in Android lacks many of the commands of its Linux counterparts. It is possible, however, to use BusyBox with Android to enable most commands to work.

Question 23

What is LFS?

Answer 23

Linux From Scratch (LFS) is more of a learning tool than a working distribution. This project consists of an online book, and source code, with “step-by-step instructions” for building a custom Linux distribution from the source code up.

This “distribution” embodies the true spirit of Linux whereby users can modify any aspect of the operating system and learn how all the pieces work together. It’s also a good starting point for anyone who needs specialized functionality or an ultra-compact build for an embedded system project.

Question 24

Explain what embedded systems are?

Answer 24

Today we call these embedded systems because they are designed to do a specific task on hardware optimized for only that purpose. These systems encompass a tremendous diversity of devices that are used today, from cell phones to smart TVs and appliances, to remote monitoring systems for pipelines and factories.

Question 25

What command would you use to display all the programs running in the background

Answer 25

Use the ps command to display all the programs running in the background:
[analyst@secOps ~]$ sudo ps –elf

Question 26

What command would you use to show process hierarchy?

Answer 26

In Linux, programs can also call other programs.

The ps command can also be used to display such process hierarchy.

Use –ejH options to display the currently running process tree after starting the nginx webserver with elevated privileges.

Note: The process information for the nginx service is highlighted. Your PID values will be different.

[analyst@secOps ~]$ sudo /usr/sbin/nginx
[analyst@secOps ~]$ sudo ps –ejH

Question 27

What is the task performed by a server called?

Answer 27

As mentioned before, servers are essentially programs, often started by the system itself at boot time.
The task performed by a server is called a service. In such fashion, a web server provides web services.

Question 28

What does the first column of the netstat output show you?

Answer 28

The first column shows the Layer 4 protocol in use (UDP or TCP, in this case).

Question 29

What does the third column of the netstat output reveal?

Answer 29

The third column uses the format to display the local IP address and port on which a specific server is reachable. The IP address 0.0.0.0 signifies that the server is currently listening on all IP addresses configured in the computer.

Question 30

What does the 4th column of the netstat output reveal?

Answer 30

The fourth column uses the same socket format to display the address and port of the device on the remote end of the connection. 0.0.0.0:* means that no remote device is currently utilizing the connection.

Question 31

What does the 5th column of the netstat output reveal?

Answer 31

The fifth column displays the state of the connection.

Question 32

What does the 6th column of the netstat output reveal?

Answer 32

The sixth column displays the process ID (PID) of the process responsible for the connection. It also displays a short name associated to the process.

Question 33

Use ps and grep to list all lines of the ps output that contain PID 2881.

Answer 33

[analyst@secOps ~]$ sudo ps -elf | grep 2881