F5 F5CAB4 BIG-IP Administration Control Plane Administration (F5CAB4) exam Exam Practice Test

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

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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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 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

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 <filepath> passphrase <password>.

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 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.

Reactivating a BIG-IP license is a traffic-disruptive operation. During the license reactivation process, the BIG-IP system performs a configuration reload, which results in a temporary interruption of all traffic processing. Because traffic handling is affected, F5 explicitly recommends scheduling license updates during a maintenance window.

This behavior is documented in F5 Knowledge Base articles, which state that license reactivation impacts traffic and must be planned accordingly during upgrades or system changes.

The other options are not considered disruptive:

Creating a QKView is primarily a diagnostic task and does not interrupt traffic.

Running tmsh save sys config only saves the running configuration to disk.

Generating a UCS is resource-intensive but does not reload configuration or interrupt traffic processing.

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.

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.

This log message indicates that the system is low on memory and has activated 'Aggressive Mode' to reclaim resources by closing old connections37. In an HA environment, one way to ensure state stability during memory pressure is to manage how connection data is handled38. While the document suggests D, procedural mitigation for 'Aggressive Mode' often involves reviewing resource provisioning or optimizing connection idle timeouts to reduce memory footprint39.

F5 Support uses a specific scale to categorize the urgency of technical issues, which helps the Control Plane management team prioritize resources effectively.

Severity 1 (Critical): Used for emergency situations where a production site is completely down, or there is a critical impact on business operations with no workaround available.

Severity 2 (High): Assigned when a system is severely degraded, or a primary function is significantly impacted, but the site remains operational in a degraded state.

Severity 3 (Medium): Applicable for issues where there is a partial loss of non-critical functionality, or the system is failing intermittently but the core business is not currently impacted.

Severity 4 (Low): This is the appropriate level for non-critical issues, general "how-to" questions, or maintenance planning. Since the administrator plans to resolve this issue in two weeks, it falls under the category of a low-priority maintenance task that does not require an immediate response from F5 support.

Reporting device status includes monitoring physical resource exhaustion, such as memory. The Control Plane provides both a command-line method via TMSH (show /sys memory) and a graphical method under Statistics > Module Statistics > Memory to report on how memory is allocated across TMM and the Linux host494949494949494949. This is essential for identifying potential "Aggressive Mode" triggers or hardware performance bottlenecks50.

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.

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

Comprehensive and Detailed Explanation From BIG-IP Administration Control Plane Admi13nistration documents:

To accurately report the current status of specific web applications hosted on the same server (node), the Control Plane must use a monitor that operates at the application layer.

Application-Specific Monitoring: While a node (the IP address) might be up and responding to ICMP (ping) or TCP handshakes, a specific web service or path on that server could be failing.

Custom Send Strings: An HTTP monitor allows the administrator to define a "Send String" to request a specific page or URI related to the application in that pool .

Receive Strings: The "Receive String" identifies a unique value that the application must return to be considered "Available" .

Granular Status Reporting: By deploying these monitors at the pool level, the Control Plane can mark a pool member "Offline" for one application pool if the receive string is missing, while keeping it "Available" in another pool where the service is still healthy.

Comprehensive and Detailed Explanation From BIG-IP Administration20 Control Plane Administration documents: Connectivity management involves ensuring that the physical layer matches the networking environment. Interface properties, including media speed, duplex settings, and MTU, are managed at the Control Plane level under the Network menu. To resolve a mismatch with an upstream switch, the administrator must navigate to Network > Interfaces to manually override auto-negotiation settings.

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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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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In netstat output:

0.0.0.0:443 means the service is bound to all available IPv4 interfaces on the system.

LISTEN indicates the service is actively waiting for incoming connection requests.

Therefore, this output confirms that a service (commonly HTTPS/443, such as the BIG-IP Configuration Utility or an application listener) is actively listening on all interfaces, making B the correct answer.

Why the other options are incorrect:

A would show 127.0.0.1:443 if it were loopback-only.

C is incorrect because LISTEN explicitly indicates readiness to accept connections.

D is unrelated; standby state does not affect socket binding shown by netstat.

Hence, the correct answer is B.