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

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

In the BIG-IP Configuration Utility,status iconsprovide immediate health information. Ared diamondspecifically indicates that theobject itself is administratively disabled. When a virtual server is disabled, BIG-IP will not accept or process traffic for that virtual server, regardless of pool or node state.

Ifall pool members were down, the virtual server would typically show ayellow triangle(available but no resources).

Ifall pool members were disabled, the virtual server would usually still be enabled but unavailable due to pool status, not shown as a red diamond.

Protocol mismatch (HTTPS sent to HTTP) doesnotchange the administrative status icon of the virtual server.

Therefore, the red diamond clearly indicates thevirtual server is disabled, makingDthe correct answer.

Comprehensive and Detailed Explanation From BIG-IP Administration Control Plane Administration documents: Audit logging is a specialized feature within TMOS designed to track administrative actions. According to F5 documentation, whenever a system object (like a virtual server, pool, or profile) is created, modified, or deleted, the system records the event. These logs are stored specifically in /var/log/audit. This is essential for control plane administration to track "who did what and when" regarding the device configuration.

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

In a BIG-IPDevice Service Cluster (DSC), manual configuration synchronization is performed using theConfigSyncframework. 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 aone-time manual ConfigSync

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

Is commonly used whenauto-sync is disabledor when the administrator wants explicit control over synchronization timing

Why the other options are incorrect:

Ais not a valid TMSH command for ConfigSync.

Benables auto-sync but doesnotperform an immediate synchronization.

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

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

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

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

Pool and pool member management

Health monitor execution

Marking pool membersUP or DOWNbased on monitor results

Events related tohealth monitor status changes, including when pool members transition betweenUPandDOWN, are logged in/var/log/ltm.

Why the other options are incorrect:

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

/var/log/securelogs authentication and authorization events.

/var/log/monitorsis 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 Explanation From BIG-IP Administration Control Plane Administration documents: When a failover occurs, the newly active device must inform the surrounding network that it now "owns" the shared IP addresses. Without MAC Masquerade, the new device uses its own hardware MAC, requiring upstream routers to update their ARP tables (which causes a delay). MAC Masquerading allows the HA pair to share a "floating" MAC address, ensuring the Control Plane transition is transparent to the network layer

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

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

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

Failing over the traffic groupmoves 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:

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

Cforces theentire deviceto 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 theTraffic Group and choosing Failoveris the correct solution.

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

In netstat output:

0.0.0.0:443means the service is bound toall available IPv4 interfaceson the system.

LISTENindicates 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) isactively listening on all interfaces, makingBthe correct answer.

Why the other options are incorrect:

Awould show 127.0.0.1:443 if it were loopback-only.

Cis incorrect because LISTEN explicitly indicates readiness to accept connections.

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

Hence, the correct answer isB.

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.

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 documents:

When restoring aUCS file to replacement hardware (RMA device), thelicense from the original device is not validon the new system. If the UCS restore attempts to load the old license, BIG-IP reports license errors such as“License is not operational”, which can prevent traffic objects (including pools and virtual servers) from loading correctly.

To avoid this issue, F5 documentation recommends restoring the UCSwithout the license, using the following command:

tmsh load /sys ucs no-license

This approach:

Restores all configuration objects (LTM, networking, certificates, keys, etc.)

Excludes the invalid license tied to the old hardware

Allows the administrator toactivate a new license separatelyon the replacement device

Why the other options are incorrect:

A. Remove the license information from the UCS archiveNot supported or recommended; UCS files should not be manually modified.

B. Revoke the license prior to restoringLicense revocation does not prevent the UCS from attempting to load license data.

D. Reactivate the license on the new device using the manual activation methodThis must be doneafterrestoring the UCS and does not prevent the restore failure itself.

Therefore, the correct and supported method to avoid this error isC.

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