The Ultimate Linux Commands And Networking Test

Which if the following tools, used for DNS debugging, reports not only the response from the name sever but also details about the query?

•  dnsq

•  hostname

•  dig

•  dnslookup

•  zoneinfo

On a machine running several X servers, how do programs identify the different instances of the X11 server?

• By a fixed UUID that is defined in the X11 configuration file.

• By a display name like: 1.

• By the name of the user that runs the X server like x11: bob.

• By a device name like /dev/X11/xservers/1.

• By a unique IPv6 address from the fe80::/64subnet.

What command list the aliases defined in the current Bash shell? (Specify only the command without any path or parameters.)

Which file inside the CUPS configuration directory contains the settings of the printers?

•  cups-devices.conf

•  snmp.conf

•  printers.conf

•  printcap.conf

•  cupsd.conf

How does the ping command work by default?

• Is sends an ICMP Echo Request to a remote host and waits to receive an ICMP Echo Response in return.

• It sends an ARP request to a remote host and waits to receive an ARP response in return.

• It sends a TCP SYN packet to a remote host and waits to receive an TCP ACK response in return.

• Is sends a broadcast packet to all hosts on the net and waits to receive, among others, a response from the target system.

• It sends a UDP packet to port 0 of the remote host and waits to receive a UDP error response in return.

Which of the following statements is true if the UID of a regular user is identical to the GID of a group?

• UID have precedence over GIDs, therefore the user is available while the group doesn’t.

• The user as well as the group are not available to avoid ambiguity due to the ID conflict.

• UIDs and GIDs are independent of each other, therefore the user as well as the group are still available.

• The user is the only member of the group, even if the group configuration contains other members.

• GIDs have precedence over UIDs, therefore the group is available while the user isn’t.

Which of the following commands lists all queued print jobs?

•  lpd

•  lpr

•  lp

•  lsq

•  lpq

What is the purpose of a screen reader?

• It manages virtual keyboards on touch screen displays.

• It reads the parameters of the attached monitors and creates an appropriate X11 configuration.

• It displays lines and markers to help people use speed reading techniques.

• It manages and displays files that contain e-books.

• It reads displayed text to accommodate the needs of blind or visually impaired people.

What output does the command seq 10 produce?

• A continuous stream of numbers increasing in increments of 10 until the command is stopped.

• It creates no output because a second parameter is missing.

• The number 0 through 9 with one number per line.

• The number 10 to standard output.

• The numbers 1 through 10 with one number per line.

Which of the following commands can identify the PID od a process which opened a TCP port?

•  ptrace

•  strace

•  debug

•  lsof

•  nessus

What is true regarding the file ~/.forward?

• When configured correctly ~/.forward can be used to forward each incoming mail to one or more other recipients.

• After editing ~/.forward the user must run newaliases to make the mail server aware of the changes.

• Using ~/.forward, root may configure any email address whereas all other users may configure only their own addresses.

• As ~/.forward is owned by the MTA and not writable by the user, it must be edited using the

• By default, only ~/.forward files of users in the group mailq are processed while all other user’s ~/.forward files are ignored.

How many IP addresses can be used for unique hosts inside the IPv4 subnet 192.168.2.128/26?

• 6

• 14

• 30

• 62

• 126

Which of the following information is stored in /etc/shadowfor each user?

• The timestamp of the user’s last login

• The user’s private SSH keys

• The hashed password of the user

• The numerical user ID (UID)

• The path to the user’s home directory

Which of the following is true regarding the command sendmail?

• With any MTA, the sendmail command must be run periodically by the cron daemon.

• When using systemd, sendmail is an alias to relayctl.

• The sendmail command prints the MTA’s queue history of which mails have been sent successfully.

• It is only available when the sendmail MTA is installed.

• All common MTAs, including Postfix and Exim, provide a sendmail command.

Which standardized TCP port is used by HTTPS services?

• 25

• 80

• 8080

• 443

• 636

What does the term Braille Display refer to?

• A standardized high contract graphical theme for desktop applications?

• A Linux desktop environment similar to KDE and GNOME.

• A legacy display technology superseded by LCD.

• A physical representation of characters using small dots.

• A standard file format for data exchange, similar to XML.

Which configuration file contains the default options for SSH clients?

•  /etc/ssh/sshd_config

•  /etc/ssh/ssh

•  /etc/ssh/ssh_config

•  /etc/ssh/client

•  /etc/ssh/ssh_client

Which of the following connection types, as seen in nmcli connection show, may exist in NetworkManager? (Choose three.)

•  tcp

•  ethernet

•  wifi

•  ipv6

•  bridge

Which of the following commands is used to rotate, compress, and mail system logs?

•  logrotate

•  striplog

•  syslogd –-rotate

•  rotatelog

•  logger

Which of the following commands displays all environment and shell variables?

•  getargs

•  lsenv

•  ls

•  env

•  lsshell

Which of the following configuration files should be modified to globally set shell variables for all users?

•  /etc/profile

•  /etc/bashrc

•  ~/.bash_profile

•  /etc/.bashrc

•  /etc/shellenv

What is the systemd journal stored?

• /var/jlog/and /var/jlogd/

• /proc/log/and /proc/klog/

• /run/log/journal/ or /var/log/journal/

• /var/log/syslog.binor /var/log/syslog.jrn

• /etc/systemd/journal/or /usr/lib/systemd/journal/

Which of the following protocols is related to the term open relay?

•  SMTP

•  POP3

•  NTP

•  IMAP

•  LDAP

What information is provided by the echo $$ command?

• The process ID of the current shell.

• The process ID for the following command.

• The process ID of the last command executed.

• The process ID of the last command which has been placed in the background.

• The process ID of the echo command.

Which of the following parameters are used for journalctl to limit the time frame of the output? (Choosetwo.)

•  --since=

•  --from=

•  --until=

•  --upto=

•  --date=

What is a purpose of an SSH host key?

• It must be sent by any SSH client in addition to a user key in order to identify the client’s host.

• It is root key by which all user SSH keys must be signed.

• It provides the server’s identity information to connecting SSH clients.

• It authenticates any user that logs into a remote machine from the key’s host.

• It is used by system services like cron, syslog or a backup job to automatically connect to remote hosts.

Given the following routing table: How would an outgoing packet to the destination 192.168.2.150 be handled?

• It would be passed to the default router 192.168.178.1 on wlan0.

• It would be directly transmitted on the device eth0.

• It would be passed to the default router 255.255.255.0 on eth0.

• It would be passed to the router 192.168.1.1 on eth0.

• It would be directly transmitted on the device wlan0.

What output is produced by the following command sequence? echo ‘1 2 3 4 5 6’ | while read a b c; do echo result $c $b $a; done

•  result: 6 5 4

•  result: 1 2 3 4 5 6

•  result: 3 4 5 6 2 1

•  result: 6 5 4 3 2 1

•  result: 3 2 1

What output does the command seq 1 5 20 produce?

• 1 5 10 15

• 1 6 11 16

• 1 2 3 4

• 2 3 4 5

• 5 10 15 20

What information related to a user account is modified using the chage command?

• Default ownership for new files

• Group membership

• Set of commands available to the user

• Password expiry information

• Default permissions for new files

Which environment variable is used by an X11 client to determine the X Server to connect to? (Specify only the variable name without any preceding commands or values.)

Depending on a system’s configuration, which of the following files can be used to enable and disable network services running on this host?

•  /etc/profile

•  /etc/xinetd.conf

•  /etc/ports

•  /etc/services

•  /etc/host.conf

The X11 configuration file xorg.conf is grouped into section. How is the content of the section SectionNamerepresented?

• It is placed in curly brackets as in Section SectionName {…}.

• It is placed between the tags <Section name=“SectionName”>and </Section>.

• It is placed between a line containing Section “SectionName”and a line containing EndSection.

• It is placed after the row [SectionName].

• It is placed after an initial unindented Section “SectionName” and must be indented by exactly one tab character.

How do shadow passwords improve the password security in comparison to standard no-shadow password?

• Regular users do not have access to the password hashes of shadow passwords.

• Every shadow password is valid for 45 days and must be changed afterwards.

• The system’s host key is used to encrypt all shadow passwords.

• Shadow passwords are always combined with a public key that has to match the user’s private key.

• Shadow passwords are stored in plain text and can be checked for weak passwords.

On a Linux workstation, the route command takes a long time before printing out the routing table. Which of the following errors does that indicate?

• The local routing information may be corrupted and must be re-validated using a routing protocol.

• One of the routers in the routing table is not available which causes the automatic router failure detection mechanism (ARF-D) to wait for a timeout.

• There may accidentally be more than one default router in which case a default router election has to be done on the network in order to choose one router as the default.

• The Linux Kernel Routing Daemon (LKRD) is not running and should be started using its init script or systemd unit.

• DNS resolution may not be working as route by default tries to resolve names of routers and destinations and may run into a timeout.

What is true about the Hop Limit field in the IPv6 header?

• The field is not changed during the transport of a package.

• The field is transmitted within a hop-by-hop extension header.

• Each router forwarding the packet increases the field’s value.

• Each router forwarding the packet decreases the field’s value.

• For multicast packages, the field’s value is always 1.

Which of the following IPv4 networks are reserved by IANA for private address assignment and private routing? (Choose three.)

• 10.0.0.0/8

• 127.0.0.0/8

• 169.255.0.0/16

• 172.16.0.0/12

• 192.168.0.0/16

Which of the following commands should be executed when starting a login shell in order to change the language of messages for an internationalized program to Portuguese (pt)?

•  export LANGUAGE=“pt”

•  export LC_MESSAGES=“pt”

•  export UI_MESSAGES=“pt”

•  export MESSAGE=“pt”

•  export ALL_MESSAGES=“pt”

If an alias ls exists, which of the following commands updates the alias to point to the command ls -l instead of the alias’s current target?

•  set ls=’ls -l’

•  alias ls=’ls -l’

•  alias --force ls=’ls -l’

•  alias --update ls ls=’ls -l’

•  realias ls=’ls -l’

Which command is used to set restrictions on the size of a core file that is created for a user when a program crashes?

•  core

•  edquota

•  quota

•  ulimit

•  ktrace

Which parameter is missing in the command ip link set ____ dev eth0 to activate the previously inactive network interface eth0? (Specify the parameter only without any command, path or additional options.)

Which of the following commands sets the system’s time zone to the Canadian Eastern Time?

•  localegen -t -f /usr/share/zoneinfo/Canada/Eastern > /etc/locate.tz

•  tzconf /etc/localtime

•  sysctl -w clock.tz=’Canada/Eastern’

•  modprobe tz_ca_est

•  ln -sf /usr/share/zoneinfo/Canada/Eastern /etc/localtime

Which of the following sections exists in a systemd timer unit?

• [Events]

• [Timer]

• [cron]

• [Schedule]

• [Trigger]

What can be specified with useradd? (Choose two.)

• Commands the user can run using sudo.

• The absolute path to the user’s home directory.

• Which printers are available for the new user.

• The SSH keys used to login to the new account.

• The numeric user ID (UID) of the user.

Which of the following steps prevents a user from obtaining an interactive login session?

• Setting the UID for the user to 0.

• Running the command chsh –s /bin/false with the user name.

• Removing the user from the group staff.

• Adding the user to /etc/noaccess.

• Creating a .nologin file in the user’s home directory.

What is the purpose of TCP wrapper?

• Manage and adjust bandwidth used by TCP services.

• Bind a network service to a TCP port.

• Encapsulate TCP messages in IP packets.

• Add SSL support to plain text TCP services.

• Limit access to a network service.

Which of the following situations is observed and corrected by an NTP client?

• The skew in time between the system clock and the computer’s hardware clock.

• The physical location and the time zone configuration.

• Changes in the time zone of the current computer’s location.

• Adjustment needed to support Daylight Saving Time.

• The skew in time between the system clock and the reference clock.

How can a specific user be prevented from scheduling tasks with at?

• By adding the specific user to the /etc/at.allowfile.

• By adding the specific user to the [deny] section in the /etc/atd.conffile.

• By adding the specific user to the nojobs group.

• By adding the specific user to the /etc/at.denyfile.

• By executing the atd --deny[user] command.