F5CAB4 Sample Questions Answers

Managing the state of a device often involves restoring configuration backups known as User Configuration Set (UCS) files These archives contain the full system configuration, including licenses and SSL certificates. The Control Plane provides a dedicated management area for these files under System > Archives, where administrators can upload, create, and restore configuration snapshots

On BIG-IP systems, authentication and authorization events are logged in /var/log/secure. This includes:

Successful and failed SSH login attempts

Invalid user authentication attempts

PAM (Pluggable Authentication Module) authentication failures

Access denials related to secure services

Why the other options are incorrect:

/var/log/messages contains general system messages and service events, not detailed authentication failures.

/var/log/audit records administrative configuration changes (who changed what and when), not login attempts.

/var/log/ltm logs traffic-management (TMM) and application-related events.

Therefore, the correct log file for investigating unauthorized SSH login attempts is /var/log/secure.

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To determine the current failover (HA) status of a BIG-IP system using tmsh, F5 documentation explicitly states that the administrator should use the following command:

show /cm failover-status

This command displays:

The current failover state (active, standby, or offline)

Detailed failover status information

The operational HA condition of the device within a device group

According to F5 Knowledge Base Article K08452454, the documented procedure for checking failover status is:

Log in to the TMOS Shell (tmsh)

Run show /cm failover-status

Why the other options are incorrect:

A. list /cm failover shows configuration settings, not operational HA status.

B. show /sys failover is not the documented command for checking current failover status and does not align with F5’s recommended procedure.

Management access security is a primary Control Plane configuration task3.

Management Interface Security: The BIG-IP system provides a dedicated management port that is separate from the TMM (Traffic Management Microkernel) data interfaces4444.

System Platform Settings: Under the System > Platform section of the Configuration Utility, an administrator can define specific IP addresses or subnets that are permitted to access the device via SSH or HTTPS (the GUI).

Port Lockdown Difference: While "Port Lockdown" settings under Network > Self IPs control access to the device through self-IP addresses on data VLANs, they do not manage the security of the dedicated management port .

Access Control Lists: For robust security, F5 recommends using the "IP Allow" or "httpd Allow" lists found in the platform settings to prevent malicious brute-force attempts or unauthorized access from non-management networks .

In the BIG-IP Configuration Utility, all system backup and restore operations—including UCS (User Configuration Set) file restoration—are performed from the Archives section.

The correct navigation path is:

System > Archives

From this location, the administrator can:

Upload UCS files

Restore UCS backups

Manage system archive files used for backup and recovery

Why the other options are incorrect:

A. System > Configuration is used for general system settings, not backup restoration.

C. Local Traffic > Virtual Servers is used for application traffic objects.

D. Local Traffic > Policies manages traffic policies, not system backups.

Therefore, the correct section to restore a UCS file using the Configuration Utility is System > Archives.

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Traffic Groups are the mechanism BIG-IP uses to control which device owns specific application traffic in a high-availability (HA) configuration. When maintenance is required on a device that is currently active for a traffic group, the correct and recommended action is to fail over that traffic group to another device in the device group.

Failing over the traffic group moves ownership of that traffic group (and the virtual servers associated with it) to another available device without forcing the entire device into standby.

This allows targeted maintenance while minimizing impact to other traffic groups that may still be active on the device.

Why the other options are incorrect:

A is unnecessary and incorrect; traffic groups are not recreated for routine maintenance.

C forces the entire device to standby, which may move more traffic than intended.

D (Demote) affects device trust/priority behavior and is not the standard or recommended method for moving traffic group ownership.

Therefore, selecting the Traffic Group and choosing Failover is the correct solution.

On BIG-IP systems that participate in a Device Service Cluster (DSC), each device compares the remote device’s system time to its own system time. If the difference is outside the ConfigSync time threshold (commonly referenced as 3 seconds by default), BIG-IP updates the shell prompt to show “Peer Time Out of Sync”, and ConfigSync operations may fail until time is corrected (typically by fixing NTP reachability/configuration, or in some cases adjusting the threshold). (cdn.studio.f5.com)

This message is specifically about time drift between peers in the trust domain/DSC—not basic reachability (so B is not what it means), and it does not prove which side is “correct” (so C is too specific). It also doesn’t directly mean an NTP source is “skewed” (A can be a cause, but the prompt message itself indicates the peer-to-peer time mismatch condition). (cdn.studio.f5.com)

When a BIG-IP Administrator changes module provisioning (for example, enabling ASM on a system previously provisioned only for LTM), the BIG-IP system must restart the Traffic Management Microkernel (TMM) process.

The TMM process is responsible for:

Traffic handling

LTM, ASM, and other traffic-processing modules

Enforcing security and application policies

Provisioning changes affect how traffic modules are loaded and integrated into TMM. As a result, TMM is restarted, which causes a temporary interruption of traffic processing. This is expected behavior and is why module provisioning changes should be planned during a maintenance window.

Why the other options are incorrect:

A. bd is related to blade/platform management, not module provisioning.

C. sshd handles SSH access and is not affected by provisioning changes.

D. httpd supports the Configuration Utility (GUI) and does not restart due to module provisioning.

Therefore, the correct answer is B. tmm.

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The Statistics Dashboard is the primary graphical interface used by administrators to monitor the real-time performance and health of the BIG-IP system.

System-Wide Overview: Navigating to Statistics > Dashboard provides a centralized view of critical system-level metrics, including global CPU utilization (across all TMM instances and the Linux host) and total memory usage.

Performance Tracking: In addition to CPU and memory, the dashboard displays other vital statistics such as total active connections, throughput (bits/packets per second), SSL transactions per second (TPS), and compression efficiency.

Operational Health: Monitoring these metrics from the dashboard allows the administrator to quickly identify performance trends or resource exhaustion that could impact the Control Plane or Data Plane stability.

Comparison to Other Menus:

Local Traffic > Virtual Servers: Provides statistics specific to traffic objects rather than global system resources.

Network > Interfaces: Shows physical layer statistics like link status, errors, and drops for specific ports.

Device Management > Overview: Focuses on high availability (HA) states, synchronization status, and device trust rather than granular performance metrics.

On BIG-IP systems, Local Traffic Manager (LTM) is responsible for:

Pool and pool member management

Health monitor execution

Marking pool members UP or DOWN based on monitor results

Events related to health monitor status changes, including when pool members transition between UP and DOWN, are logged in /var/log/ltm.

Why the other options are incorrect:

/var/log/audit records administrative configuration changes, not runtime health status.

/var/log/secure logs authentication and authorization events.

/var/log/monitors is not a standard BIG-IP log file.

Therefore, the correct log file for pool member health monitor status events is /var/log/ltm.

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Monitoring and reporting current device status involves tracking the health of traffic objects like Virtual Servers20. The Control Plane logs transition events—such as a Virtual Server moving from 'Available' (green) to 'Offline' (red) due to health monitor failures—in the /var/log/ltm file21212121. While the audit log tracks who changed a configuration, the LTM log tracks system-initiated status changes22222222.

The BIG-IP Control Plane monitors the "Commit ID" of the configuration on all group members. When a change is made on the Standby unit, it becomes the member with the most recent configuration. The "Recommended Action" in the HA status dashboard will be to synchronize that specific device's configuration to the rest of the group to ensure consistency

Comprehensive and Detailed Explan13ation From BIG-IP Administration Control Plane Administration documents: Monitoring the physical status of the device is critical for reporting device health. In F5 nomenclature, "1.0", "1.1", etc., represent physical hardware interfaces. To verify if a physical link is up or down as reported by the Control Plane's SNMP agent, the administrator must check the Interface List located under Network > Interfaces

Comprehensive and Detailed Explanation From BIG-IP Administration Control Plane Administration do38cuments: While HA state is managed under "Device Management," the specific failover behavior of a traffic object is linked to its configuration. A Virtual Address must be associated with a "Traffic Group" (usually traffic-group-1) to fail over. This association and the resulting floating status can be verified by viewing the Virtual Server or Virtual Address list under Local Traffic > Virtual Servers.

The User Configuration Set (UCS) is a flexible tool designed by the Control Plane to handle various lifecycle management scenarios, including upgrades and hardware migrations.

Version Compatibility (Option B): TMOS is designed to be backward compatible. The Control Plane can ingest a UCS file created on an older version of software and automatically upgrade the configuration objects to match the current, later version during the restore process.

Platform Portability (Option C): While a UCS archive contains platform-specific information, the BIG-IP system allows for "platform-independent" restores. This is a vital procedural concept for migrating from one hardware model to another or from physical hardware to a Virtual Edition (VE).

Management of State: When restoring to a different platform or a later version, the administrator often uses specific flags (such as no-license or platform-migrate in later versions) to ensure that only the portable configuration data is applied while preserving the new platform's unique identifiers.

Managing the license is a primary Control Plane task required to activate software modules and features on a BIG-IP device.

License Management Utility: All actions related to the device license, including initial activation, renewal, and adding add-on keys, are performed under the System > License section of the Configuration Utility.

Procedural Requirements: Licensing often requires the generation of a "dossier," which is a unique encrypted string used by the F5 License Server to generate the final license file.

Impact on Services: Updating or re-activating a license generally requires a restart of system services (such as the tmm daemon), which will temporarily disrupt traffic processing unless performed on a standby unit in a high availability pair.

Add-on Licenses: If an administrator needs to increase the capacity of a specific module (like increasing the SSL TPS limit or adding a new module like ASM), the new registration keys are entered through this same interface using the "Re-activate" button.

In a BIG-IP Device Service Cluster (DSC), manual configuration synchronization is performed using the ConfigSync framework. The supported and documented command to manually push the local configuration to a specific device group is:

tmsh run cm config-sync to-group

This command:

Initiates a one-time manual ConfigSync

Pushes the local device’s configuration to all members of the specified device group

Is commonly used when auto-sync is disabled or when the administrator wants explicit control over synchronization timing

Why the other options are incorrect:

A is not a valid TMSH command for ConfigSync.

B enables auto-sync but does not perform an immediate synchronization.

D is not a valid or supported TMSH command for device group configuration synchronization.

Therefore, the correct command to manually synchronize configuration to a device group is C.

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