LPIC-2 Network Client Management Practice Test 4 — 15 Questions

Question 1

An administrator is configuring a DHCP server using ISC dhcpd to provide addresses to a subnet with many mobile devices. The administrator wants to ensure that the DHCP server does not assign addresses that are already in use by statically configured devices. Which TWO methods can the administrator use to prevent IP address conflicts? (Choose two.)

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Use the ping-check statement to have dhcpd ping an address before offering it.. Two effective methods to prevent IP conflicts are using the ping-check statement, which tests addresses before assignment, and defining static host declarations while excluding those addresses from dynamic ranges. These approaches ensure that statically configured devices are not affected by DHCP assignments.

Answer

Set the authoritative directive and use the dhcpd -t option to test the configuration.

Answer

Define a range that excludes the static addresses, and use the deny members of "static" class or similar to prevent assignment.

Answer

Configure the DHCP server to use OMAPI to query a database of static addresses.

Question 2

An administrator manages a DHCP server with ISC dhcpd on a Linux host. A new subnet 192.168.10.0/24 needs dynamic address assignment, but the administrator must ensure that the DHCP server only responds to requests from known clients on that subnet and that clients always receive the same IP address based on their MAC address. Which configuration directive should be used within the subnet declaration to meet these requirements?

Accepted Answer

host printer { hardware ethernet 00:11:22:33:44:55; fixed-address 192.168.10.50; }. To meet both requirements—restricting responses to known clients and ensuring consistent IP assignment based on MAC—a host declaration with hardware ethernet and fixed-address is needed. This defines a specific client and its permanent lease. While deny unknown-clients can filter clients, it does not assign fixed addresses. The combination of a host declaration inside the subnet achieves both goals.

Answer

range 192.168.10.100 192.168.10.200;

Answer

option routers 192.168.10.1;

Answer

deny unknown-clients;

Question 3

An administrator is configuring a Linux client to use Kerberos authentication for SSH logins. The client has a valid keytab file at /etc/krb5.keytab. Which TWO steps are required to enable GSSAPI authentication for SSH on the client? (Choose two.)

Accepted Answer

Set 'GSSAPIAuthentication yes' in /etc/ssh/ssh_config.. To enable GSSAPI authentication for SSH, the SSH client configuration must include 'GSSAPIAuthentication yes' in /etc/ssh/ssh_config, and the SSH server configuration must include the same in /etc/ssh/sshd_config. Both are necessary for the client to initiate and accept GSSAPI authentication. The keytab permissions and DNS are prerequisites but not the configuration steps themselves.

Answer

Ensure the keytab file has permissions 0600 and is owned by root.

Answer

Configure reverse DNS for the client and server in /etc/hosts.

Answer

Add 'pam_krb5.so' to /etc/pam.d/sshd.

Question 4

A Debian server has the following /etc/network/interfaces stanza:

auto eth0
iface eth0 inet dhcp

The administrator needs eth0 to keep its DHCP-assigned address for at least 24 hours before attempting renewal, and to use the hostname 'web01' in DHCP requests. Which directive should be added to the iface stanza to request a long lease and set the client hostname?

Accepted Answer

hostname web01
lease-time 86400. The ifupdown framework allows client-specific DHCP options inside an iface stanza. The hostname keyword sets the DHCP client hostname, and lease-time defines the requested lease duration in seconds. 86400 seconds corresponds to 24 hours. Adding hostname web01 and lease-time 86400 causes the DHCP client to request the desired lease and identify itself with the correct name, which is exactly what the administrator needs.

Answer

dhcp-hostname web01 and dhcp-lease-time 86400

Answer

dhcp-host web01

Answer

hostname web01 and lease-time 86400

Question 5

A junior administrator needs to configure a Linux client to use an NTP server at ntp.example.com for time synchronization. The system uses systemd. Which command will set the NTP server and enable synchronization?

Accepted Answer

Edit /etc/systemd/timesyncd.conf to set NTP=ntp.example.com and restart systemd-timesyncd. On a systemd-based system, time synchronization is handled by systemd-timesyncd. The NTP= setting in /etc/systemd/timesyncd.conf defines the NTP servers. After modifying the file, restarting systemd-timesyncd ensures the new server is used and synchronization is active. This is the standard, persistent way to configure a specific NTP server.

Answer

timedatectl set-ntp true

Answer

ntpdate ntp.example.com

Answer

chronyc add server ntp.example.com

Question 6

An administrator is configuring a Linux client to use an NIS domain for user authentication. The NIS server is at nis.example.com, and the domain is 'example'. Which TWO steps are required to complete the client configuration? (Choose two.)

Accepted Answer

Set the NIS domain name with the domainname command or in /etc/sysconfig/network. To configure an NIS client, the NIS domain name must be set so the client knows which domain to join, and the ypbind daemon must be running to bind to a server. These two steps are essential for the client to communicate with the NIS server. While updating /etc/nsswitch.conf is also necessary, the question asks for two steps, and setting the domain name and starting ypbind are the fundamental configuration actions that enable NIS functionality.

Answer

Create a local user account for each NIS user

Answer

Add 'nis' to the passwd, shadow, and group lines in /etc/nsswitch.conf

Answer

Edit /etc/nsswitch.conf to include 'nis' for the relevant databases

Question 7

An administrator needs to configure a Linux client to automatically obtain an IP address from a DHCP server but also ensure that the client uses a specific static DNS server (8.8.8.8) regardless of the DHCP-provided DNS. Which configuration should be applied?

Accepted Answer

Add 'supersede domain-name-servers 8.8.8.8;' to /etc/dhcp/dhclient.conf. The `supersede` directive in `/etc/dhcp/dhclient.conf` forces the DHCP client to replace any DNS server addresses received from the DHCP server with the specified value (8.8.8.8). This ensures the client uses the static DNS server regardless of what the DHCP server offers, while still obtaining its IP address dynamically.

Answer

Add 'append domain-name-servers 8.8.8.8;' to /etc/dhcp/dhclient.conf

Answer

Edit /etc/sysconfig/network-scripts/ifcfg-eth0 and set PEERDNS=no and DNS1=8.8.8.8

Answer

Add 'prepend domain-name-servers 8.8.8.8;' to /etc/dhcp/dhclient.conf

Question 8

Which file is used by the NetworkManager daemon to store connection profiles on a Linux system?

Accepted Answer

/etc/NetworkManager/system-connections/. NetworkManager stores per-connection profiles in the `/etc/NetworkManager/system-connections/` directory. Each profile is a keyfile (`.nmconnection` file) containing connection parameters such as SSID, security settings, and IP configuration. When NetworkManager starts or a connection is modified, it reads and writes these files to persist network configurations across reboots.

Answer

/etc/sysconfig/network-scripts/

Answer

/etc/netctl/

Answer

/etc/systemd/network/

Question 9

A Linux client is configured with two network interfaces: eth0 (connected to the internet) and eth1 (connected to a private LAN). The default route is set to eth0. The client can access the internet but cannot access hosts on the private LAN. What is the most likely cause?

Accepted Answer

There is no route to the private subnet via eth1.. Without a route to the private subnet via eth1, the client has no way to forward packets destined for the private LAN out of eth1. The default route via eth0 only handles traffic for destinations not explicitly matched by other routes; if the private subnet is not in the routing table, packets to that subnet will be sent to the default gateway (internet) and fail. The `ip route` command would show the missing entry, and adding a static route (e.g., `ip route add 192.168.1.0/24 dev eth1`) resolves the issue.

Answer

A firewall on the client is blocking ICMP packets on eth1.

Answer

The eth1 interface is not configured with an IP address.

Answer

The eth1 interface is not receiving a DHCP lease.

Question 10

Which TWO configuration files are commonly used to specify DNS resolver settings on a Linux system? (Select TWO.)

Accepted Answer

/etc/systemd/resolved.conf. Option B, /etc/systemd/resolved.conf, is correct because it is the configuration file for systemd-resolved, the DNS resolver service on modern systemd-based Linux distributions, where settings such as DNS=, FallbackDNS=, and Domains= specify the DNS servers used for name resolution. Option C, /etc/resolv.conf, is correct because it is the traditional and still widely used file that lists DNS resolver settings via the nameserver, search, and options directives, and it is read by the resolver library (glibc) for DNS queries. Option A, /etc/nsswitch.conf, is not a DNS resolver settings file; it controls the order in which name service sources (e.g., files, dns, nis) are consulted via the hosts: line, but it does not specify DNS server addresses. Option D, /etc/dhcp/dhclient.conf, configures the DHCP client, and while it can influence how DNS information is obtained (e.g., via supersede or request options), it is not itself a DNS resolver settings file. Option E, /etc/hosts, is a static local hostname-to-IP mapping file, not a DNS resolver configuration file.

Answer

/etc/nsswitch.conf

Answer

/etc/dhcp/dhclient.conf

Answer

/etc/hosts

Question 11

A company has a Linux client running Ubuntu 20.04 that is used by multiple developers. The client has two network interfaces: eth0 (connected to the corporate network with DHCP) and eth1 (connected to a test lab with static IP 192.168.100.10/24). The client needs to access both the internet (via eth0) and the lab network (192.168.100.0/24). The default gateway is 10.0.0.1 on eth0. The lab network has a server at 192.168.100.50 that provides DHCP for the lab devices, but the client's eth1 is statically configured. Recently, the client cannot reach the lab server at 192.168.100.50. The administrator checks the routing table and sees:

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         10.0.0.1        0.0.0.0         UG    100    0        0 eth0
10.0.0.0        0.0.0.0         255.255.255.0   U     100    0        0 eth0
192.168.100.0   0.0.0.0         255.255.255.0   U     100    0        0 eth1

The administrator can ping 192.168.100.50 from the client. However, the lab server cannot ping the client. What is the most likely cause?

Accepted Answer

The client's firewall is blocking incoming ICMP echo requests.. The client can ping the lab server (192.168.100.50), proving that outbound traffic from the client to the lab network works correctly. However, the lab server cannot ping the client, which indicates that either the return traffic is blocked or the client does not have a route back to the server. Since the client's routing table shows a direct route to 192.168.100.0/24 via eth1, the issue is not a missing route; instead, the most likely cause is that the client's firewall (e.g., iptables or ufw) is blocking incoming ICMP Echo Requests (ping) on eth1, while allowing outbound traffic.

Answer

The lab server's default gateway is misconfigured.

Answer

The client has no route to the lab subnet.

Answer

The client's default gateway is misconfigured.

Question 12

Which TWO commands can be used to display the current IP address and netmask of network interfaces on a Linux system?

Accepted Answer

ifconfig. Option B (ifconfig) is correct because the legacy net-tools command ifconfig, when run without arguments, prints each network interface's inet address and netmask (e.g., inet 192.168.1.10 netmask 255.255.255.0). Option C (ip addr show) is correct because the modern iproute2 command ip addr show (equivalently ip a) displays each interface's inet/inet6 addresses with their prefix length, which represents the netmask. Option A (arp -a) only lists the ARP cache mapping IP addresses to MAC addresses, not interface addresses or netmasks. Option D (netstat -i) shows interface statistics and flags but not IP addresses or netmasks. Option E (route -n) displays the kernel routing table in numeric form, not the addresses and netmasks assigned to interfaces.

Answer

arp -a

Answer

netstat -i

Answer

route -n

Question 13

Arrange the steps to perform a disaster recovery from a full system backup using tar.

Accepted Answer

Boot into rescue mode, then prepare disks, then mount the root filesystem, then extract backup using tar, then reboot.. The correct sequence for disaster recovery from a full system backup using tar ensures a logical progression: first gain access to a recovery environment (rescue mode), then prepare the storage devices, mount the target filesystem, restore the data from the backup archive, and finally reboot to the restored system. Any deviation leads to errors such as missing filesystem or incomplete restoration.

Answer

Boot into rescue mode, then mount the root filesystem, then prepare disks, then extract backup using tar, then reboot.

Answer

Boot into rescue mode, then prepare disks, then extract backup using tar, then mount the root filesystem, then reboot.

Answer

Boot into rescue mode, then prepare disks, then mount the root filesystem, then reboot, then extract backup using tar.

Question 14

A user reports they cannot obtain an IP address via DHCP. The DHCP server logs show no client activity, but the network cable is connected. Which configuration is most likely missing on the DHCP server?

Accepted Answer

subnet declaration. The DHCP server logs show no client activity, meaning the server is not receiving DHCPDISCOVER packets from the client. The most likely missing configuration is a subnet declaration, which defines the network segment the DHCP server should listen on and allocate addresses from. Without a matching subnet declaration in the DHCP configuration (e.g., /etc/dhcp/dhcpd.conf), the server will ignore requests from that subnet, even if the physical cable is connected.

Answer

deny unknown-clients

Answer

default-lease-time

Answer

option domain-name

Question 15

An administrator wants to restrict access to a service using PAM. Which file order determines the authentication flow for a service?

Accepted Answer

/etc/pam.d/<service-name>. PAM (Pluggable Authentication Modules) uses per-service configuration files located in /etc/pam.d/ to define the authentication flow. When a service (e.g., sshd, login) calls PAM, it reads the file named after the service (e.g., /etc/pam.d/sshd) to determine the order of modules (auth, account, password, session) and their control flags (required, requisite, sufficient, optional). This file-based approach allows fine-grained, service-specific authentication policies.

Answer

/etc/nsswitch.conf

Answer

/etc/security/access.conf

Answer

/etc/pam.conf