LPIC-1 Practice Test 15 — 15 Questions

Question 1

A company is deploying a new web application and needs to ensure high availability. They have two web servers and want to use DNS round-robin. Which DNS record type is most appropriate?

Accepted Answer

A. DNS round-robin distributes traffic across multiple servers by returning multiple A records for a single hostname in a rotating order. An A record maps a hostname to an IPv4 address, so using multiple A records for the same name is the standard method for DNS-based load balancing. This allows each web server to be reached via its own IP address, enabling high availability without additional hardware or software.

Answer

MX

Answer

PTR

Answer

CNAME

Question 2

You are responsible for maintaining a legacy Red Hat Enterprise Linux 6 server that hosts an internal web application. The application was compiled years ago and relies on an old version of OpenSSL (0.9.8). Due to a security audit, you must update OpenSSL to 1.0.1 but the application fails to run with the new version. The vendor no longer supports the application. You must keep the system secure while keeping the application operational. You have access to the application source code but cannot modify it. What is the best solution?

Accepted Answer

Install OpenSSL 1.0.1 in /usr/local/lib and keep 0.9.8 in /usr/lib. Rebuild the application with an RPATH pointing to /usr/local/lib/openssl0.9.8.. It allows you to install OpenSSL 1.0.1 in a separate path (/usr/local/lib) while keeping the legacy 0.9.8 in /usr/lib. By rebuilding the application with an RPATH pointing to /usr/local/lib/openssl0.9.8, you force the dynamic linker to load the old OpenSSL library only for that application, satisfying the security audit for the rest of the system while keeping the unmodifiable application operational.

Answer

Modify the application source code to be compatible with OpenSSL 1.0.1 and recompile.

Answer

Update OpenSSL system-wide and use 'LD_PRELOAD' to load the old library for the application.

Answer

Keep OpenSSL 0.9.8 and accept the risk.

Question 3

Refer to the exhibit. The system has multiple SAS drives attached to this controller, but one of them is not detected during boot. Which command is most likely to provide information about the device detection order?

Accepted Answer

dmesg | grep -i scsi. The `dmesg` command displays kernel ring buffer messages, which include hardware detection and initialization logs during boot. By piping to `grep -i scsi`, you filter for SCSI-related messages, revealing the order in which devices were discovered and any errors for undetected drives. This is the most direct way to see why a specific SAS drive failed to appear.

Answer

cat /proc/scsi/scsi

Answer

lsblk

Answer

lsscsi

Question 4

An organization's DNS server (BIND) is authoritatively serving the example.com zone. The administrator needs to add a mail exchange record for mail.example.com with priority 10. Which resource record should be added to the zone file?

Accepted Answer

example.com. IN MX 10 mail.example.com.. An MX record specifies the mail exchange server for a domain, and the syntax 'example.com. IN MX 10 mail.example.com.' defines a priority of 10 for the mail server mail.example.com. This record tells other mail servers to deliver email for @example.com to mail.example.com, with lower priority values preferred.

Answer

mail.example.com. IN A 192.168.1.10

Answer

mail.example.com. IN CNAME example.com.

Answer

example.com. IN TXT "v=spf1 mx -all"

Question 5

Which TWO of the following commands output the total number of lines in a file?

Accepted Answer

sed -n '$='. The `sed -n '$='` command prints the line number of the last line of the file, which is equivalent to the total number of lines. The `wc -l` command counts the number of newline characters, which directly gives the total line count. Both commands output the total number of lines in a file.

Answer

grep -c '.'

Answer

nl

Answer

head -n 1

Question 6

Refer to the exhibit. Which of the following is true about SSH access to this server?

Accepted Answer

User 'charlie' is denied access regardless of authentication method.. The exhibit shows an SSH configuration with a `DenyUsers charlie` directive, which explicitly blocks user 'charlie' from any SSH access regardless of the authentication method (password, public key, etc.). This directive takes precedence over any other authentication settings, making option A correct.

Answer

User 'alice' can authenticate using a password.

Answer

Password authentication is disabled for all users.

Answer

Root can log in with a password.

Question 7

A security administrator needs to allow SSH access from the 10.0.0.0/8 network but deny all other traffic to port 22. The firewall uses iptables with default policy ACCEPT on the INPUT chain. Which set of rules should be added?

Accepted Answer

iptables -A INPUT -s 10.0.0.0/8 -p tcp --dport 22 -j ACCEPT; iptables -A INPUT -p tcp --dport 22 -j DROP. Iptables processes rules in order, and the first match determines the action. By placing the ACCEPT rule for the 10.0.0.0/8 source first, traffic from that network is allowed. The subsequent DROP rule for all other traffic to port 22 ensures that any packet not matching the first rule is denied, effectively implementing the required allow-from-specific-source, deny-all-others policy.

Answer

iptables -A INPUT -p tcp --dport 22 -j DROP; iptables -A INPUT -s 10.0.0.0/8 -p tcp --dport 22 -j ACCEPT

Answer

iptables -A INPUT -s 10.0.0.0/8 -p tcp --dport 22 -j DROP; iptables -A INPUT -p tcp --dport 22 -j ACCEPT

Answer

iptables -A INPUT -s 10.0.0.0/8 -p tcp --dport 22 -j ACCEPT

Question 8

Refer to the exhibit. The system administrator sees that /var/log is 93% full and the syslog file is nearly 2 GB. What is the most appropriate immediate action to free up disk space without losing any critical log data?

Accepted Answer

Run 'logrotate -f /etc/logrotate.conf' to force log rotation.. 'logrotate -f' forces an immediate rotation of all log files as defined in /etc/logrotate.conf, which compresses or archives the current syslog file (e.g., syslog becomes syslog.1) and creates a fresh empty log file. This frees disk space without deleting any data, as the rotated logs remain on disk until the configured retention policy removes them. It is the standard, safe immediate action for a nearly full /var/log partition.

Answer

Increase the size of the /var/log partition using lvextend.

Answer

Delete /var/log/syslog and restart the syslog daemon.

Answer

Move /var/log/syslog to /tmp and create a symbolic link.

Question 9

Which TWO conditions would cause the boot process to fall back to the GRUB rescue shell? (Choose two.)

Accepted Answer

The GRUB modules are not loaded from the correct path.. The GRUB rescue shell is entered when the core image cannot locate its modules, typically due to an incorrect module path. This prevents GRUB from loading its normal configuration, causing a fallback to the minimal rescue shell. Missing or corrupt grub.cfg, on the other hand, leads to the GRUB normal shell (grub>), not the rescue shell. Other issues like missing kernel, initramfs, or BIOS failure occur after GRUB or before it starts, so they do not trigger the rescue shell.

Answer

The kernel image is not found in /boot.

Answer

The BIOS cannot find a bootable device.

Answer

The initramfs is missing or corrupt.

Answer

The /boot/grub/grub.cfg file is missing or corrupt.

Question 10

A system administrator wants to install custom scripts that should be available to all users. The scripts are not part of any package and should be placed under the Filesystem Hierarchy Standard (FHS). Which directory is most appropriate?

Accepted Answer

/usr/local/bin. /usr/local/bin because the Filesystem Hierarchy Standard (FHS) designates /usr/local as the location for locally installed software not managed by the system's package manager. Placing custom scripts in /usr/local/bin ensures they are in the default PATH for all users, while keeping them separate from system binaries in /usr/bin and /bin.

Answer

/var

Answer

/opt

Answer

/home

Question 11

A system has a software RAID1 array (/dev/md0) with two disks: /dev/sda and /dev/sdb. Disk /dev/sda fails. Which command sequence will replace the failed disk with a new /dev/sdc without stopping the array?

Accepted Answer

mdadm --manage /dev/md0 --fail /dev/sda --remove /dev/sda && mdadm --manage /dev/md0 --add /dev/sdc. Mdadm's --manage mode allows hot-replacement of a failed disk in a RAID1 array without stopping it. The --fail flag marks /dev/sda as faulty, --remove detaches it, and --add incorporates the new /dev/sdc, triggering an automatic rebuild of the mirror.

Answer

mdadm --stop /dev/md0; replace disk; mdadm --assemble /dev/md0 /dev/sdb /dev/sdc

Answer

Shutdown system, physically replace disk, reboot

Answer

dd if=/dev/sdb of=/dev/sdc bs=64K

Question 12

Refer to the exhibit. An administrator is trying to install Google Chrome but receives a GPG error. Which command should be run to add the repository's GPG key?

Accepted Answer

`wget -qO- https://dl.google.com/linux/linux_signing_key.pub | sudo apt-key add -`. It downloads the Google Linux signing key from the official URL and pipes it directly into `apt-key add`, which imports the key into APT's trusted keyring. This resolves the GPG error by allowing APT to verify the authenticity of packages from the Google Chrome repository.

Answer

`gpg --import https://dl.google.com/linux/linux_signing_key.pub`

Answer

`apt-key adv --keyserver keyserver.ubuntu.com --recv-keys <keyid>`

Answer

`dpkg --add-key google`

Question 13

Which TWO configuration files are commonly associated with NTP client configuration?

Accepted Answer

/etc/chrony.conf. B is correct because `/etc/chrony.conf` is the configuration file for the `chronyd` NTP client daemon, which is the default NTP implementation on modern RHEL/CentOS 8+ and many other distributions. D is correct because `/etc/ntp.conf` is the traditional configuration file for the `ntpd` NTP daemon, used by the `ntp` package on older systems and still common on Debian/Ubuntu. Both files define NTP server pools, drift files, and other synchronization settings.

Answer

/etc/systemd/timesyncd.conf

Answer

/etc/timezone

Answer

/etc/ntpd.conf

Question 14

After running 'ip route show default', a system administrator sees no output. Users on that system can only communicate with hosts on the local subnet. What is the most likely cause?

Accepted Answer

The default gateway is missing. The `ip route show default` command displays the default gateway entry in the routing table. An empty output indicates that no default route is configured. Without a default gateway, the system cannot route packets to destinations outside its local subnet, which explains why users can only communicate with hosts on the local subnet.

Answer

DNS is misconfigured

Answer

A firewall is blocking all traffic

Answer

The network interface is down

Question 15

A shell script uses the variable expansion ${var:-default} to set a default value for an environment variable. The script prints unexpected output when the variable is set to an empty string. Which expansion should be used to ensure the default is only used when the variable is unset, not when it is empty?

Accepted Answer

${var-default}. The expansion `${var-default}` uses the default value only when the variable is unset (i.e., does not exist at all). In contrast, `${var:-default}` also substitutes the default when the variable is set but empty, which causes the unexpected output described in the question. The colon in the expansion is the critical difference: it adds the check for a null or empty string.

Answer

${var:-default}

Answer

${var:?default}

Answer

${var:=default}