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

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.

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, 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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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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A BIG-IP device group cannot be deleted if it still contains device members, even if one of those devices has already been decommissioned or is unreachable. Before deleting the device group, the administrator must explicitly remove the decommissioned device from the device group configuration.

Once the removed or unreachable device is deleted from the device group membership, the BIG-IP system allows the remaining administrator to successfully delete the device group.

Why the other options are incorrect:

A. Remove all members from the device groupThis is not required; the key requirement is removing the decommissioned device, not all members.

B. Make sure all members are in syncSynchronization status does not prevent device group deletion.

D. Disable the device groupDevice groups cannot be disabled; they must be modified or deleted.

Therefore, the correct prerequisite action is to remove the decommissioned device from the device group, making C the correct answer.

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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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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."

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.

Time synchronization is a critical component of Control Plane management, as it ensures that logs are accurately timestamped and that High Availability (HA) trust relationships remain valid1.

Configuration Location: The list of configured NTP (Network Time Protocol) servers and their status is managed under System > Configuration > Device > NTP .

Procedural Importance: If the system clock drifts significantly between two devices in an HA pair, the Control Plane may experience a "Time Delta" error33. This drift often causes a failure in device trust, preventing the ConfigSync process from functioning correctly.

System Integrity: Accurate time is also essential for the validity of SSL/TLS certificates used for both administrative management access and high availability communication.

Verification: Administrators can use this section of the Configuration Utility to confirm that the BIG-IP is communicating with its designated upstream time sources and that the local clock is correctly synchronized to the network environment .

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 the BIG-IP Configuration Utility, status icons provide immediate health information. A red diamond specifically indicates that the object 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.

If all pool members were down, the virtual server would typically show a yellow triangle (available but no resources).

If all 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) does not change the administrative status icon of the virtual server.

Therefore, the red diamond clearly indicates the virtual server is disabled, making D the correct answer.

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.

To re27port the current status of high availability for specific traffic, an administrator must verify the Traffic Group association28. In the Configuration Utility, Virtual Server properties include the Virtual Address settings where the 'Traffic Group' is assigned29292929. If the Virtual Address is assigned to a floating traffic group (like traffic-group-1), it is configured to fail over to the standby member30303030.

watch-devicegroup-device shows (among other columns) the commit ID (cid.id / shown here as clu_id), the originating device for that commit (cid-orig / shown here as cl_orig), and the time the configuration change was made (cid.time / shown here as cl_time). The highest/newest commit ID and its time represent the most recent configuration change seen among the devices. (clouddocs.f5.com)

bigip_a has the latest configuration (A) because it shows commit ID 3273 at 14:27:00, which is newer than commit ID 1745 at 13:52:34 on bigip_b and bigip_c. (clouddocs.f5.com)

Two devices are out of date (B) because bigip_b and bigip_c are still on the older commit ID 1745, so they do not match the latest commit shown on bigip_a. (clouddocs.f5.com)

Why the other options are not supported by this output:

C is not supported: bigip_c is not showing a newer commit than the others; it’s on the older commit (1745), so it’s not the source of the most recent change. The output’s cid-orig column is what tells you where the change was made. (clouddocs.f5.com)

D/E are incorrect logic: matching cid.time between two devices only indicates they share the same change timestamp/commit, not that it is the correct or latest configuration. The “latest” is indicated by the newest commit ID/time (here, bigip_a). (clouddocs.f5.com)

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.

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.

On a BIG-IP system, remote syslog server configuration is managed through the logging configuration framework. In the Configuration Utility, this is accessed via:

System > Logs > Configuration

This section allows the administrator to:

Define remote syslog destinations

Configure log publishers

Control which log types (system, audit, LTM, ASM, etc.) are forwarded to external syslog servers

Why the other options are incorrect:

A. System > Configuration > Local TrafficUsed for traffic management settings, not logging.

C. System > Logs > AuditDisplays audit log settings and content but does not configure remote syslog destinations.

D. System > Configuration > DeviceUsed for device-level settings such as hostname and platform configuration, not logging.

Therefore, the correct location to reconfigure BIG-IP to send logs to new syslog servers is System > Logs > Configuration.

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