F5CAB4 Practice Test 2 — 10 Questions

Question 1

An administrator needs to restrict administrative access to the BIG-IP system so that only specific source IP addresses can reach the Configuration Utility. Which feature should be configured to ensure this security requirement?

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

Accepted Answer

Update the Management IP Allow list in System Configuration.. Restricting management access via the Management IP allows administrators to define a whitelist of trusted networks. This is a critical security practice in F5 Control Plane Administration to prevent unauthorized access to the management plane from untrusted segments. By using the 'Allow' list under System > Configuration > Device > Management IP, the BIG-IP will drop any packets originating from non-authorized IPs, effectively securing the administrative interface from external threats.

Answer

Enable Packet Filtering on the external VLAN.

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Configure an iRule to drop traffic on the management port.

Answer

Modify the global Firewall policy for the Data Plane.

Question 2

Refer to the exhibit. Why is it important for the administrator to review the 'show sys hardware' output when troubleshooting a control plane issue?

Accepted Answer

It verifies that the control plane has access to sufficient physical resources.. Hardware status directly informs the administrator about resource capacity, such as CPU cores or memory, which are critical for the control plane. If hardware components are failing (e.g., memory errors, fan failure), it can manifest as sluggish GUI response or mcpd instability. Reviewing this output helps differentiate between software configuration issues and underlying hardware stress, which is essential for accurate diagnostics and determining whether an RMA or physical maintenance is required.

Answer

It displays the current traffic throughput of all virtual servers.

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It lists the active users currently logged into the device.

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It is required to update the system's licensing information.

Question 3

Which log file is most useful for troubleshooting administrative login attempts and authentication failures on the BIG-IP control plane?

Accepted Answer

/var/log/secure. The /var/log/secure log file is the standard Linux repository for authentication-related events. On a BIG-IP, this includes SSH access, GUI login attempts, and PAM-related authentication activities. Monitoring this file is essential for F5 administrators to detect brute-force attacks, troubleshoot credential issues, and maintain a secure control plane by keeping track of who is accessing the device and when.

Answer

/var/log/ltm

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/var/log/messages

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/var/log/audit

Question 4

A BIG-IP administrator is preparing to upgrade the TMOS software on a device. Before the upgrade, the administrator must ensure that the current configuration is backed up and that the device can be restored if the upgrade fails. Which tmsh command creates a full configuration backup archive that can be used for restoration?

Accepted Answer

save sys ucs /var/local/ucs/backup.ucs. A UCS archive is the standard full backup format on BIG-IP, containing configuration, licenses, and certificates. The save sys ucs command creates this archive and can be directed to a specific path. Other commands either save only the running configuration to standard files or are not valid tmsh commands for creating backups.

Answer

create sys backup /var/local/ucs/backup.ucs

Answer

export sys config /var/local/ucs/backup.ucs

Answer

save sys config /var/local/ucs/backup.ucs

Question 5

A BIG-IP administrator is configuring a new device and needs to set up the control plane to allow remote management via SSH and HTTPS. The administrator wants to ensure that only secure protocols are used and that access is restricted to specific management IP addresses. Which two actions should the administrator take? (Choose two.)

Accepted Answer

Enable SSH and disable Telnet access on the management interface.. To secure remote management, the administrator should enable SSH and disable Telnet, and configure a management port lockdown to restrict access to specific IP addresses. These actions ensure that only secure protocols are used and that access is limited to authorized addresses, meeting the security requirements.

Answer

Enable HTTP access and disable HTTPS access to improve performance.

Answer

Configure the management IP address and management route using tmsh.

Answer

Set up a default route for the management interface.

Question 6

An administrator needs to securely transfer a large UCS file from the BIG-IP management plane to a remote backup server. Which method is most secure and appropriate for this control plane task?

Accepted Answer

SCP. Using SCP or SFTP over SSH provides an encrypted channel for file transfer, ensuring that the configuration archive, which may contain sensitive keys and passwords, is not exposed in cleartext. This is standard procedure for maintaining secure control plane operations, preventing potential data leaks when moving sensitive configuration backups across the management network to an off-site or secure central storage location.

Answer

FTP

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HTTP

Answer

TFTP

Question 7

An F5 administrator is tasked with updating the BIG-IP software version. Which pre-update control plane check is the most critical for ensuring a successful deployment?

Accepted Answer

Verify sufficient disk space on all partitions.. Verifying the health of the control plane before an upgrade is essential to prevent bricking the system. Checking disk space, running process health, and ensuring configuration integrity ensures that the upgrade process has the necessary resources and can properly migrate existing settings. This is a vital step because an upgrade failure can lead to an extended outage and complicated recovery scenarios, making thorough validation an absolute requirement for stable operations.

Answer

Clear the browser cache on the management PC.

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Restart all virtual servers.

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Rename the default 'admin' account.

Question 8

An administrator observes that the BIG-IP system's management interface is experiencing high CPU utilization. Which process should the administrator investigate first to determine if control plane operations are impacting system performance?

Accepted Answer

mcpd. The 'mcpd' (Master Configuration Program Daemon) is the central authority for all BIG-IP configuration. High CPU usage in mcpd typically indicates massive configuration changes, sync operations, or excessive API calls. Monitoring mcpd is essential because it manages the transition of configuration data to TMM; performance issues here suggest that the control plane is struggling to process administrative updates or communicate with the data plane components effectively.

Answer

TMM

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sshd

Answer

bigd

Question 9

Refer to the exhibit. The administrator encounters a 'database is locked' error while attempting to push a configuration change. What is the most likely cause?

Accepted Answer

Another administrative task is currently modifying the configuration database.. The 'database is locked' error in mcpd typically occurs when another administrative process, such as a concurrent TMSH transaction, a scheduled sync, or an automated API task, currently holds a write lock on the configuration database. Since mcpd requires exclusive access to apply changes, any competing operation prevents new writes. This matters because it highlights the necessity of managing concurrent control plane tasks to prevent configuration corruption and ensure atomic updates.

Answer

The TMM process has crashed and is holding a mutex on the mcpd socket.

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The disk partition hosting /var/config is full, preventing write operations.

Answer

The SSH daemon has been compromised, leading to unauthorized file locks.

Question 10

Which user role provides the highest level of access within the BIG-IP system, allowing full control over all modules and the underlying Linux operating system?

Accepted Answer

Administrator. The 'Administrator' role is the top-tier access level, granting full control over every aspect of the system. This level of access is necessary for performing system-wide updates, changing core configurations, and managing other users. Understanding the scope of this role is crucial, as it entails significant responsibility for system stability and security, and it must be managed carefully by authorized personnel to prevent accidental or malicious system-wide changes.

Answer

Operator

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Manager

Answer

Resource Administrator