Deck 14: Troubleshooting, Performance, and Security

Question 1

Select the iptables option that specifies the destination address of packets for a rule:

A) -D
B) -L
C) -F
D) -d

Answer 1

D

Question 2

Which command can be used to see what network services are running on your network?

A) nmap
B) map
C) networkmap
D) nm

Answer 2

A

Question 3

What utility in the sysstat package measures the flow of information to and from disk devices?​

A) ​mpstat
B) ​iostat
C) ​iodump
D) ​drivemon

Answer 3

B

Question 4

Older hardware that is malfunctioning may begin to send large amounts of information to the CPU when not in use. What is this process called?​

A) ​flooding
B) ​hiccuping
C) jabbering​
D) ​dumping

Question 5

How often are sar commands scheduled to run on both Fedora 20 and Ubuntu Server 14.04?

A) every two minutes
B) every five hours
C) every ten minutes
D) every thirty days

Question 6

What option can be specified with the rpm command to identify any missing files in a package or package dependency?

A) -v
B) -m
C) -V
D) -M

Question 7

Performance problems are caused by hardware, not software.

Question 8

Performing regular system backups and identifying potential problem areas are examples of reactive maintenance.

Question 9

Almost all hardware problems are the result of damaged hardware.

Question 10

What is the most common hardware component to fail on a Linux system?

A) Floppy drives
B) Hard disks
C) NICs
D) Video cards

Question 11

If the / filesystem becomes corrupted, the system is unstable and must be turned off.

Question 12

By default, the shell on a Linux system limits the number of filehandles a program can have open to what value?

A) 256
B) 512
C) 1024
D) 2048

Question 13

What file contains the DSA public key in the /etc/ssh directory?

A) ssh_host_dsa_key
B) ssh_host_dsa_key. pub
C) ssh_target_dsa_key
D) ssh_target_dsa_key.pub

Question 14

Select the option that, when used with the sar command, displays swap statistics:

A) -B
B) -b
C) -s
D) -q

Question 15

What option for the iptables command can be used to specify the default policy for a certain chain type?

A) -P
B) -C
C) -p
D) -c

Question 16

Running background processes using what command allows you to exit your command-line shell without ending any background processes?

A) continue
B) noshell
C) nokill
D) nohup

Question 17

If applications run into difficulties gaining resources during execution and stop functioning, restarting the process using a specific kill signal may resolve the issue. Select the proper kill signal below:

A) SIGINT
B) SIGQUIT
C) SIGTERM
D) SIGHUP

Question 18

If network services that are started by inetd or xinetd are in use, what can be used to provide extra security?

A) network bootstrapper
B) TCP wrapper
C) IP wrapper
D) daemon launcher

Question 19

Which sar command option is used to display statistics for the processor queue?

A) -r
B) -c
C) -q
D) -v

Question 20

If some users, such as software developers, need to run certain commands as the root user in certain situations, it is best to allow them to log on to the root user account via the su command.

Question 21

Assistive technologies are configured using what utility on Fedora 20 in GNOME?​

A) ​Universal Access
B) ​Accessibility
C) ​Usability
D) ​Access Helper

Question 22

​What command can be used to view what shared libraries are required by a certain program?

A) ​ldconfig
B) ldlist
C) ldd​
D) ​showlibs

Question 23

After downloading an installing any shared libraries, what should be done to ensure ​the list of shared library directories and the list of shared libraries are updated?

A) ​Check the /lib, /lib64, /usr/lib, or /usr/lib64 directories for the library.
B) ​Run the ldconfig command.
C) ​Run a program that uses the shared libraries.
D) ​Perform a system restart.

Question 24

What are the two golden rules that should guide you during any troubleshooting process? Describe each rule.

Question 25

​Match each term with the correct statement below.
a.​baseline
b.buffer overrun​
c.​file handles
d.​firewall daemon (firewalld)
e.​Intrusion Detection System (IDS)
f.​lsof command
g.​nmap command
h.​SSH agent
i.​tunneling
j.tripwire
​A command that lists the files that are currently being viewed or modified by software programs and users.

Question 26

What command can be used to change the maximum number of file handles that can be used by a program?​

A) ​fhlimit
B) ​pgmod
C) ​fhch
D) ulimit​

Question 27

​Match each term with the correct statement below.
a.​baseline
b.buffer overrun​
c.​file handles
d.​firewall daemon (firewalld)
e.​Intrusion Detection System (IDS)
f.​lsof command
g.​nmap command
h.​SSH agent
i.​tunneling
j.tripwire
​A program that can be used to detect unauthorized access to a Linux system.

Question 28

What methods can be used to physically secure local computers?

Question 29

The ____________________ command is used to view the current SELinux status.

Question 30

​Match each term with the correct statement below.
a.​baseline
b.buffer overrun​
c.​file handles
d.​firewall daemon (firewalld)
e.​Intrusion Detection System (IDS)
f.​lsof command
g.​nmap command
h.​SSH agent
i.​tunneling
j.tripwire
​The process of embedding network packets within other network packets.

Question 31

When performance issues arise, you can compare the output of performance utilities to the ____________________ values found in the system log book.

Question 32

Viewing the output of the ____________________ command, journalctl -b command, or the contents of the /var/log/boot.log and /var/log/messages log files can isolate most hardware problems.

Question 33

How is the mpstat utility used? What information does it provide, and how can that information be interpreted?

Question 34

Processes can initiate numerous connections, called ____________________, to files on the filesystem in addition to standard input, standard output, and standard error.

Question 35

​Match each term with the correct statement below.
a.​baseline
b.buffer overrun​
c.​file handles
d.​firewall daemon (firewalld)
e.​Intrusion Detection System (IDS)
f.​lsof command
g.​nmap command
h.​SSH agent
i.​tunneling
j.tripwire
​A measure of normal system activity.

Question 36

​Match each term with the correct statement below.
a.​baseline
b.buffer overrun​
c.​file handles
d.​firewall daemon (firewalld)
e.​Intrusion Detection System (IDS)
f.​lsof command
g.​nmap command
h.​SSH agent
i.​tunneling
j.tripwire
​The connections that a program makes to files on a filesystem.

Question 37

Some peripheral devices can perform a great deal of processing that is normally performed by the CPU; this is known as ____________________.

Question 38

​If X Windows fails to start, what command can be used to troubleshoot the issue?

A) ​xstatus
B) ​xwininfo
C) ​xdetail
D) ​xreload

Question 39

How can you identify filesystem corruption? How should you troubleshoot filesystem corruption on a non-critical partition?

Question 40

How can netfilter/iptables be used to create a firewall service?

Question 41

​On a system that is not using Systemd, what two log files contain information related to PAM?

A) ​/var/log/pam.log
B) ​/var/log/secure
C) ​/var/log/auth.log
D) ​/var/log/messages

Question 42

​Match each term with the correct statement below.
a.​baseline
b.buffer overrun​
c.​file handles
d.​firewall daemon (firewalld)
e.​Intrusion Detection System (IDS)
f.​lsof command
g.​nmap command
h.​SSH agent
i.​tunneling
j.tripwire
A common IDS for Linux that monitors files and directories.​

Question 43

​Match each term with the correct statement below.
a.​baseline
b.buffer overrun​
c.​file handles
d.​firewall daemon (firewalld)
e.​Intrusion Detection System (IDS)
f.​lsof command
g.​nmap command
h.​SSH agent
i.​tunneling
j.tripwire
​A software program that can be used to automatically authenticate users using their private key.

Question 44

​Match each term with the correct statement below.
a.​baseline
b.buffer overrun​
c.​file handles
d.​firewall daemon (firewalld)
e.​Intrusion Detection System (IDS)
f.​lsof command
g.​nmap command
h.​SSH agent
i.​tunneling
j.tripwire
​An attack in which a network service is altered in memory

Question 45

What two iptables options are used to specify the source and destination ports for a rule?​

A)​-sport
B)-dport
C)​-src
D)​-dst

Question 46

​What are the two most common technologies that provide asymmetric encryption on Linux systems?

A) ​Apache httpd
B) ​Secure Shell (SSH)
C) ​Telnet
D) ​GNU Privacy Guard (GPG)

Question 47

​What two commands below can display memory information and swap usage?

A) ​memtop
B) ​free
C) ​swap_stat
D) ​vmstat

Question 48

​Match each term with the correct statement below.
a.​baseline
b.buffer overrun​
c.​file handles
d.​firewall daemon (firewalld)
e.​Intrusion Detection System (IDS)
f.​lsof command
g.​nmap command
h.​SSH agent
i.​tunneling
j.tripwire
​A command that can be used to scan ports on network computers.

Question 49

​Asymmetric encryption uses a pair of keys that are unique generated on each system. What are these two keys called?

A) ​normal key
B) ​public key
C) ​secret key
D) ​private key

Question 50

​Match each term with the correct statement below.
a.​baseline
b.buffer overrun​
c.​file handles
d.​firewall daemon (firewalld)
e.​Intrusion Detection System (IDS)
f.​lsof command
g.​nmap command
h.​SSH agent
i.​tunneling
j.tripwire
A daemon used on some Linux systems to provide for easier configuration of netfilter via the ipchains command.​