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

On BIG-IP systems, all authentication attempts for administrative access—including logins to the Configuration Utility (GUI) —are logged in /var/log/secure . This log file records:

Successful and failed login attempts

The username used

The authentication method (local, LDAP, RADIUS, etc.)

Access denials and PAM authentication errors

Why the other options are incorrect:

/var/log/pam/tallylog tracks account lockouts and failed attempt counters, not detailed login attempts.

/var/log/ltm logs traffic management events, not administrative authentication.

/var/log/httpd logs web server activity but does not record authentication success or failure for BIG-IP administrative users.

Therefore, the correct log file to verify whether a user attempted to log in to the BIG-IP Configuration Utility is /var/log/secure .

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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

The Control Plane is responsible for ARP (Address Resolution Protocol) management for Virtual Addresses. For a Virtual Server to be reachable, the BIG-IP must respond to ARP requests for that IP. If the " ARP " setting is disabled on the Virtual Address properties, upstream routers cannot resolve the MAC address of the BIG-IP, leading to connectivity failure even if the service itself is " Available. "

Identifying the current device status includes knowing which software modules (such as LTM, ASM, or APM) are active and how much hardware resource (CPU/Memory) is allocated to them 40404040 . The System > Resource Provisioning screen displays the licensing status and allows the administrator to set the provisioning level (Nominal, Dedicated, or Minimum) for each module.

Comprehensive and Detailed Explanation From BIG-IP Administration Control Plane Adminis44tration documents: In a45n Active/Standby HA pair, application traffic only flows through the Active device. If an administrator makes a change on the Standby device (which has no traffic), they must synchronize the configuration to the Active device to test it. The procedural step is to log into the Active device and " pull " the configuration from the Standby device (or push from Standby) so the Active device can process traffic using the new iRule

BIG-IP provides two supported and documented methods to manually force a device into standby state in a high-availability (HA) configuration:

CLI method (A) :

tmsh run /sys failover device standby

This is the correct and supported TMSH command to force the local device to transition from active to standby .

Configuration Utility method (B) : Navigating to Device Management > Devices > Local Device (Self) and selecting Force to Standby performs the same operation through the GUI and is fully supported.

Why the other options are incorrect:

C is incorrect : Traffic Groups do not provide a “Force to Standby” option for the local device; traffic groups are used to manage which device owns specific traffic, not to force device-level failover.

D is incorrect : tmsh run /sys failover standby is not a valid TMSH command . The correct syntax requires device standby.

Thus, the correct answers are A and B .

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.

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 of the device ' s identity and primary out-of-band connectivity is a central Control Plane responsibility.

Platform Settings : The System > Platform section of the Configuration Utility is used to manage global hardware and system parameters, including the hostname, management IP address, and time zone.

Management vs. Data Plane : It is critical to distinguish between the management interface and TMM data interfaces. While data plane IPs (Self IPs) are configured under Network > Self IPs , the dedicated management port settings are grouped with other platform-level configurations.

Access Control : This area is also used to manage administrative security, such as restricting SSH or HTTPS access to specific management subnets or IP addresses.

Impact of Change : Changing the management IP will immediately disconnect any active GUI or SSH sessions using the current management IP. The administrator must reconnect using the newly assigned address.

Managing how a BIG-IP communicates with external management services like Syslog is a core Control Plane task. The Configuration Utility organizes these settings under the " System " menu. Specifically, to define remote logging destinations and formats, the administrator must navigate to System > Logs > Configuration to ensure the Control Plane correctly forwards system events to external collectors

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 < device_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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On a BIG-IP system, NTP (Network Time Protocol) configuration is part of the system-level configuration settings . In the Configuration Utility, NTP servers are configured under the System configuration hierarchy .

The correct navigation path is:

System > Configuration > Device > NTP

This location allows the administrator to:

Add, modify, or remove NTP servers

Ensure accurate system time synchronization

Maintain proper time alignment required for features such as ConfigSync , HA failover , logging, and certificate validation

Why the other options are incorrect:

A. System > Platform is used for hardware-related settings.

B. System > Preferences manages UI and user preferences.

C. System > Services controls system daemons and services, not time configuration.

Therefore, the correct answer is D. System > Configuration .

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Maintaining an accurate and synchronized clock across all members of a device group is a fundamental requir5ement for the BIG-IP Control P6lane to establis7h and maintain device tru8st9.

Time Delta Impact : As shown in the exhibit, the " Time Delta to Local Device (sec) " is 12 .

Trust Mechanism : Device trust relies on secure certificate-based communication (SSL/TLS) . If the time difference between devices is too large (typically more than a few seconds), the Control Plane cannot validate the certificates, leading to a failure in the trust relationship .

ConfigSync Failure : When device trust is broken due to time drift, the systems cannot verify the identity of the peer, which directly prevents the ConfigSync process from executing on the affected device, such as bigip3.local in this scenario.

Resolution : Administrators must ensure that all devices in a high availability pair are configured to use the same reliable NTP servers to keep their system clocks aligned.

The correct command for restoring an encrypted UCS archive via the command line is D. load /sys ucs <</b> filepath > passphrase <</b> password > .