F5CAB4 BIG-IP Administration Control Plane Administration (F5CAB4) exam Questions and Answers

Although /var/log/ltm is primarily associated with Local Traffic Manager events, it is also the primary destination for system-level alerts generated by the Control Plane's chmand (Chassis Manager Daemon). Hardware status changes, including power supply failures, fan speeds, and temperature warnings, are logged as "notice" or "critical" events within the LTM log file.

NTP (Network Time Protocol) is vital for management connectivity and HA state synchronization. Correct time is required for log timestamping and device trust group communication46. To manage these settings, the administrator navigates to System > Configuration, where general system-level services like NTP and DNS are defined to ensure the Control Plane remains synchronized with the network environment.

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.

Comprehensive and Detailed Exp11lanation From BIG-IP Administration Control Plane Administration documents: Monitoring specific object health is a core function of the Control Plane. While the dashbo12ard provides a global overview, granular per13formance data—such as the CPU overhead a specific Virtual Server is placing on the Traffic Management Microkernel (TMM)—is found under the Module Statistics. Navigating to Statistics > Module Statistics > Local Traffic > Virtual Servers allows an administrator to report on the current status and resource consumption of individual traffic objects.

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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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 Administratio24n Control Plane Administration documents: TMOS Device Service Cluste25ring (DSC) allows for configuration changes to be made on any device within a synchronization group. If Auto-Sync is enabled, the Control Plane detects the change on the Standby unit and automatically propagates (pushes) that updated configuration to the other members of the HA pair

In a High Availability pair, the "Force to Standby" action is a Control Plane command used to trigger a manual failover. This option is only logical and available on the device that is currently in the Active state. If the button is greyed out, it indicates that the administrator is already logged into the Standby unit, which has no active traffic groups to relinquish.

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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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.

The EUD is a 33hardware-level diagnostic tool that runs outside of the TMOS operating system. Because it is used when the system cannot boot or is in a pre-boot state, it cannot be accessed via the GUI or management network. The administrator must connect physically via the serial Console Port to interact with the boot menu and initiate the hardware tests.

Generating a QKView is a standard procedure for identifying device health and upgrade readiness42. Within the Configuration Utility, this Control Plane diagnostic tool is located under System > Support43. This utility collects configuration and state data into a single file used by the iHealth 'Upgrade Advisor' to report on known bugs or compatibility issues prior to a version change.

F5 architecture distinguishes between the Data Plane (TMM processing application traffic) and the Control Plane (Linux host processing management tasks). High Control Plane CPU utilization typically points to administrative activities such as heavy GUI usage, complex API calls (iControl), large-scale configuration synchronizations, or intensive logging/monitoring tasks rather than the actual switching or load balancing of application data.

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.

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.

In F5 TMOS, a User Configuration Set (UCS) is the standard archive format used for backing up and migrating a complete system configuration .

Composition: A UCS file contains all necessary configuration data, including system-specific files, license information, SSL certificates, private keys, and local user accounts.

Procedural Use: When migrating to new hardware or performing an RMA replacement, the UCS file is the primary tool used to restore the entire Control Plane state to the new device.

Restoration: It can be managed through the Configuration Utility under System > Archives or via the CLI using the tmsh load /sys ucs command

The correct location to restrict management access to specific subnets is D. System > Platform1.

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.