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

Question 1

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

Accepted Answer

ifconfig. Both `ifconfig` and `ip addr show` can display the current IP address and netmask assigned to network interfaces. `ifconfig` is a legacy tool from the net-tools package that shows IPv4 addresses and netmasks (e.g., `inet 192.168.1.10 netmask 255.255.255.0`). `ip addr show` is the modern replacement from the iproute2 package, providing detailed IPv4 and IPv6 addressing information, including netmask in CIDR notation (e.g., `192.168.1.10/24`).

Answer

arp -a

Answer

netstat -i

Answer

route -n

Question 2

You are troubleshooting a Linux client that is unable to connect to the internet. The client is configured to use DHCP on interface eth0. The output of 'ip addr show eth0' shows that the interface has an IP address 192.168.1.100/24, but there is no default gateway. The output of 'ip route show' shows only the local subnet route. The DHCP server is at 192.168.1.1 and is functioning correctly. You have verified that the DHCP client (dhclient) is running, and the lease file /var/lib/dhclient/dhclient-eth0.leases exists and contains option routers 192.168.1.1. Which of the following commands should you run to resolve the issue?

Accepted Answer

dhclient -r eth0 && dhclient eth0. The DHCP client has already obtained a lease with the correct gateway (192.168.1.1), but the default route was not applied. Running `dhclient -r eth0` releases the current lease, and `dhclient eth0` renews it, forcing the client to re-apply all options from the lease, including the default gateway route. This is the standard way to reinitialize the interface's network configuration from the DHCP server without restarting the entire networking service.

Answer

systemctl restart networking

Answer

ip route del default

Answer

ip route add default via 192.168.1.1

Question 3

Which TWO tools can be used to configure network interfaces on a Linux system?

Accepted Answer

nmcli. A is correct because `nmcli` is the command-line tool for controlling NetworkManager, which is the standard service for managing network interfaces on modern Linux distributions. It allows you to create, modify, and activate or deactivate network connections, making it a primary tool for interface configuration.

Answer

route

Answer

ifconfig

Answer

netstat

Question 4

Based on the exhibit, which command would change the DNS server to 1.1.1.1 for the connection MyConnection?

Accepted Answer

nmcli con mod MyConnection ipv4.dns 1.1.1.1. The `nmcli con mod` command modifies an existing connection profile, and the `ipv4.dns` property sets the DNS server for IPv4. The property name is case-sensitive and must be lowercase `ipv4.dns` as per NetworkManager's D-Bus API. This command replaces any existing DNS servers with the specified value.

Answer

nmcli con mod MyConnection IP4.DNS 1.1.1.1

Answer

nmcli dev mod eth0 ipv4.dns 1.1.1.1

Answer

nmcli con mod MyConnection +ipv4.dns 1.1.1.1

Question 5

You are a system administrator at a small company. The network uses DHCP to assign IP addresses to clients. Recently, some users reported intermittent network connectivity issues. Upon investigation, you notice that the DHCP server is running on a Linux server with the ISC DHCP daemon. The server log shows many 'DHCPREQUEST' messages from a particular MAC address with frequent changes in requested IP addresses. Users with that MAC address are experiencing IP address conflicts and connectivity drops. What is the most likely cause and the best corrective action?

Accepted Answer

Identify the device with that MAC address and replace its network interface card.. The frequent DHCPREQUEST messages from the same MAC address requesting different IP addresses indicate a faulty network interface card (NIC) that is generating random or corrupted DHCP requests, likely due to hardware malfunction. Replacing the NIC eliminates the root cause by stopping the spurious traffic, whereas other options only mask symptoms or fail to address the hardware fault.

Answer

Increase the DHCP lease time to reduce the frequency of renewals.

Answer

Add a static DHCP mapping for the problematic MAC address to a reserved IP.

Answer

Restart the DHCP daemon to clear the lease database.

Question 6

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 7

Match each NFS version to its feature.

Accepted Answer

NFSv2: Stateless protocol using UDP, limited to 32-bit file handles. NFS versions evolved from stateless NFSv2 (UDP, 32-bit) to NFSv3 (TCP, 64-bit, async writes) to stateful NFSv4 (compound RPC, security, delegation). Common confusions include attributing v4 features to v2 and v2 limitations to v3.

Answer

NFSv2: Introduced compound RPC and stateful operations

Answer

NFSv3: Limited to UDP and 32-bit file handles

Question 8

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 9

An administrator configures LDAP authentication on a Linux client. After making changes to /etc/nsswitch.conf and /etc/pam.d/system-auth, users can log in but cannot execute commands like 'id username'. What is the most likely cause?

Accepted Answer

nsswitch.conf lacks 'ldap' for passwd. The 'id username' command relies on the Name Service Switch (NSS) to resolve user and group information from configured sources. If 'ldap' is not listed for the 'passwd' database in /etc/nsswitch.conf, the system will not query the LDAP server for user account details, even though PAM may have been configured to authenticate against LDAP. This mismatch allows login (via PAM) but prevents user attribute lookups (via NSS).

Answer

LDAP server is not reachable

Answer

LDAP binddn is missing

Answer

PAM configuration is incorrect

Question 10

A Linux server exports a directory /data via NFS to a client. The client mounts it with 'mount -t nfs server:/data /mnt/data'. Write operations from the client fail with 'Permission denied' on some files. The server's /etc/exports contains: /data 192.168.1.0/24(rw,root_squash). What is the most likely issue?

Accepted Answer

root_squash maps root to nobody. The 'root_squash' option in /etc/exports maps the UID 0 (root) on the client to the 'nobody' user (typically UID 65534) on the server. When a client user with UID 0 attempts to write to files owned by other users or with restrictive permissions, the server sees the request as coming from 'nobody', which lacks write access, resulting in 'Permission denied'. This is the most likely cause because the client mount command does not specify 'no_root_squash', and the server's export explicitly enables root squashing.

Answer

NFS version mismatch

Answer

Client mount option 'noexec'

Answer

Missing 'rw' option in /etc/exports

Question 11

A Samba share is configured with 'valid users = @staff' but users in the staff group still get 'NT_STATUS_ACCESS_DENIED' when accessing the share. The server uses 'security = user'. Which additional configuration is required?

Accepted Answer

Run smbpasswd -a for each user. With 'security = user', Samba requires each user to have a separate Samba password stored in the smbpasswd file (or another passdb backend). Even if a user is a member of the 'staff' group and exists in the system's /etc/passwd, they cannot authenticate to the share without an smbpasswd entry. Running 'smbpasswd -a' for each user creates that entry, resolving the NT_STATUS_ACCESS_DENIED error.

Answer

Set 'guest ok = yes'

Answer

Set 'force group = staff'

Answer

Add the share to [global]

Question 12

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

Question 13

A company uses NIS for user authentication. A client cannot log in with network accounts but local accounts work. Which command should be used to check if the client is bound to the NIS domain?

Accepted Answer

ypwhich. The `ypwhich` command is used to display the NIS server to which the client is currently bound. If the client is not bound to any NIS domain, `ypwhich` returns an error, confirming the binding issue. This directly checks the NIS client-server binding, which is essential for network authentication.

Answer

ypset

Answer

ypcat passwd

Answer

domainname

Question 14

A DHCP server is configured to serve multiple subnets but only clients on one subnet receive IP addresses. The server is connected to a router that does not forward DHCP broadcasts. What should be configured to support the other subnets?

Accepted Answer

Set up a DHCP relay agent on the other subnets. The router does not forward DHCP broadcasts, so clients on other subnets cannot reach the DHCP server. A DHCP relay agent (e.g., `dhcrelay` or `ip helper-address`) intercepts broadcast requests on those subnets and forwards them as unicast to the DHCP server, allowing the server to assign addresses from the appropriate subnet pools. This is the standard solution per RFC 1542 when routers do not support BOOTP forwarding.

Answer

Add more subnet declarations to the DHCP server

Answer

Add 'shared-network' declarations

Answer

Configure the router to act as a DHCP server

Question 15

An administrator wants to automatically mount home directories from an NFS server when a user logs in. Which service should be configured?

Accepted Answer

autofs. Autofs is the correct service because it provides on-demand mounting of NFS home directories triggered by user login. It uses the automount daemon to mount directories only when accessed, reducing network overhead and avoiding permanent mount entries in /etc/fstab. This is the standard Linux solution for dynamic NFS home directory mounting.

Answer

rpcbind

Answer

smb

Answer

nfs