Free Practice Questions for F5 F5CAB4 Exam

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.

In F5 TMOS, administrative roles and user permissions are partition-specific. The User Manager role allows an account to manage other user accounts, but this authority is restricted to the administrative partitions to which the User Manager has been granted access.

Partition Awareness: If User1 (the User Manager) attempts to modify User2 and fails, while the full Administrator succeeds, it indicates that User2 resides in a partition where User1 does not have management rights.

Principle of Least Privilege: This principle dictates that a user should be given only the minimum level of access necessary to perform their job functions.

Procedural Solution: Granting "Administrator" privileges (Option B) would violate least privilege by giving User1 full control over all system settings and all partitions. Moving users between partitions (Options A and C) might disrupt the organizational security structure. The correct and most secure administrative action is to modify the partition access for User1 to include the partition where User2 is located. This enables User1 to manage User2’s properties while maintaining their restricted role as a User Manager.

Comprehensive and Detailed Explanation From BIG-IP Administration Con10trol Plane Administration documents: Placing a device in the FORCED_OFFLINE state is a critical procedural concept for HA maintenance111213. 1415Unlike simply being 'Standby16', the FORCED_OFFLINE state ensures tha17t the Control Plane will not participate in failover selection, effectively preventing the device from becoming 'Active' even if the peer fails18. This state also allows the administrator to terminate existing connections to ensure no traffic is being processed during the maintenance window19.

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.

Connectivity management requires a proper logical-to-physical mapping within the BIG-IP Control Plane.

VLAN Association: In TMOS, a Self IP address is not assigned directly to a physical interface. Instead, it is assigned to a VLAN (Virtual Local Area Network) object.

Procedural Troubleshooting: If a Self IP is unreachable, the primary failure point is often that the IP was associated with the wrong VLAN, or the VLAN itself is not correctly associated with the intended physical interface or trunk.

Layer 2 Mapping: The Control Plane requires the VLAN to be "up" and "untagged" or "tagged" on a valid interface for traffic to flow. If the administrator selects the incorrect VLAN, the Self IP will exist in the configuration but will be logically isolated from the physical network wire.

Management access security is a primary Control Plane configuration task3.

Management Interface Security: The BIG-IP system provides a dedicated management port that is separate from the TMM (Traffic Management Microkernel) data interfaces4444.

System Platform Settings: Under the System > Platform section of the Configuration Utility, an administrator can define specific IP addresses or subnets that are permitted to access the device via SSH or HTTPS (the GUI).

Port Lockdown Difference: While "Port Lockdown" settings under Network > Self IPs control access to the device through self-IP addresses on data VLANs, they do not manage the security of the dedicated management port .

Access Control Lists: For robust security, F5 recommends using the "IP Allow" or "httpd Allow" lists found in the platform settings to prevent malicious brute-force attempts or unauthorized access from non-management networks .

When restoring a User Configuration Set (UCS) file, BIG-IP allows administrators to selectively exclude the license during the restore process. From the CLI, this is accomplished using the no-license option with the tmsh load /sys ucs command.

The command:

tmsh load /sys ucs no-license

restores:

System configuration

Certificates and keys

Device and traffic objects

while explicitly excluding the license file, which is required when:

Migrating configurations between devices

Restoring to hardware with a different license

Avoiding license conflicts or overwrites

Why the other options are incorrect:

A does not provide the option to exclude the license.

B restores the UCS including the license, which does not meet the requirement.

D is incorrect because the BIG-IP GUI does not provide a checkbox to exclude the license during UCS restore.

Therefore, the correct and supported method is C.

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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.

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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