(2026) F5CAB4 Dumps and Practice Test (73 Questions)
Guide (New 2026) Actual F5 F5CAB4 Exam Questions
F5 F5CAB4 Exam Syllabus Topics:
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NEW QUESTION # 31
A BIG-IP Administrator needs to export system configuration for migration purposes. Which file type should be used?
- A. UCS
- B. ISO
- C. QKView
- D. SCF
Answer: A
Explanation:
In F5 TMOS, a User Configuration Set (UCS) is the standard archive format used for backing up and migrating a complete system configuration .
Composition: A UCS file contains all necessary configuration data, including system-specific files, license information, SSL certificates, private keys, and local user accounts.
Procedural Use: When migrating to new hardware or performing an RMA replacement, the UCS file is the primary tool used to restore the entire Control Plane state to the new device.
Restoration: It can be managed through the Configuration Utility under System > Archives or via the CLI using the tmsh load /sys ucs command
NEW QUESTION # 32
Administrative user accounts have been defined on the remote LDAP server and are unable to log in to the BIG-IP device. Which log file should the BIG-IP Administrator check to find the related messages?
- A. /var/log/ltm
- B. /var/log/user.log
- C. /var/log/messages
- D. /var/log/secure
Answer: D
Explanation:
Authentication and authorization events are handled by the system's PAM (Pluggable Authentication Modules). For Control Plane security auditing, all login attempts--whether local or remote (LDAP/RADIUS/TACACS+)--and SSH-related security events are recorded in
/var/log/secure. This is the primary log for troubleshooting administrative access issues
NEW QUESTION # 33
Users are unable to reach an application. The BIG-IP Administrator checks the Configuration Utility and observes that the Virtual Server has a red diamond in front of the status.
What is causing this issue? (Choose one answer)
- A. All pool members are down
- B. The Virtual Server is receiving HTTPS traffic over an HTTP virtual
- C. All pool members have been disabled
- D. The Virtual Server is disabled
Answer: D
Explanation:
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.
NEW QUESTION # 34
The BIG-IP Administrator runs the command:
netstat -an | grep 443
and sees the following output:
tcp 0 0 0.0.0.0:443 0.0.0.0:* LISTEN
What does this output indicate about the service on port 443? (Choose one answer)
- A. The service is in a standby state and unable to accept connections.
- B. The service is actively listening on all interfaces for HTTPS traffic.
- C. The service is actively listening only on the loopback interface.
- D. The service indicates no connections to the LISTEN port.
Answer: B
Explanation:
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.
NEW QUESTION # 35
An LTM device has a virtual server mapped to www.f5.com. Users report that when they connect to /resources
/201.1.2h.l_l.com they are unable to receive content. What is the likely cause of the issue?
- A. The pool associated with the virtual server is falling its health check.
- B. The virtual address does not have route advertising enabled.
- C. The virtual address does not have ARP enabled.
- D. The pool associated with the virtual server does not have priority group activation enabled.
Answer: C
Explanation:
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."
NEW QUESTION # 36
As an organization grows, more people have to log into the BIG-IP. Instead of adding more local users, the BIG-IP Administrator is asked to configure remote authentication against a central authentication server. Which two types of remote server can be used here? (Choose two answers)
- A. OAUTH
- B. LDAP
- C. RADIUS
- D. SAML
Answer: B,C
Explanation:
BIG-IP supports remote authentication by integrating with centralized authentication services through its AAA framework. The supported and commonly used remote authentication servers include:
LDAP (A)
Used to authenticate users against directory services such as Active Directory or other LDAP- compliant directories.
RADIUS (C)
Commonly used for centralized authentication, authorization, and accounting, especially in network and security environments.
NEW QUESTION # 37
A BIG-IP Administrator needs to restore an encrypted UCS archive from the command line using the TMSH utility. Which TMSH command should the BIG-IP Administrator use to accomplish this?
- A. load /sys ucs <filepath> no-license
- B. load /sys config file <filepath> passphrase <password>
- C. load /sys ucs <filepath> passphrase <password>
- D. load /sys config file <filepath>
Answer: C
Explanation:
Restoring system states from backups is a fundamental Control Plane administrative task. When a User Configuration Set (UCS) archive is created with encryption, it requires the correct passphrase to be decrypted and loaded during the restoration process.
UCS Command Structure: The tmsh load /sys ucs command is the specific utility for restoring these comprehensive configuration archives.
Encrypted Restores: If the archive was encrypted during creation, the passphrase argument must be appended to the command followed by the actual password used to encrypt the file.
NEW QUESTION # 38
What can the BIG-IP Administrator do when restoring BIG-IP configuration files with a UCS archive? (Choose two answers)
- A. The BIG-IP Administrator can restore a UCS archive on a BIG-IP system running a later software version than the version of software the UCS archive was created on.
- B. The BIG-IP Administrator can restore a UCS archive on a BIG-IP system on a different platform.
- C. The BIG-IP Administrator can only restore a UCS archive on a BIG-IP system running the same version.
- D. The BIG-IP Administrator can only restore the UCS archive to the same system from which it was saved.
Answer: A,B
Explanation:
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.
NEW QUESTION # 39
Users report that traffic is negatively affected every time a BIG-IP device fails over. The traffic becomes stabilized after a few minutes. What should the BIG-IP Administrator do to reduce the impact of future failovers?
- A. Configure a global SNAT Listener
- B. Configure MAC Masquerade
- C. Set up Failover Method to HA Order
- D. Enable Failover Multicast Configuration
Answer: B
NEW QUESTION # 40
A BIG-IP Administrator suspects that one of the BIG-IP device power supplies is experiencing power outages. Which log file should the BIG-IP Administrator check to verify the suspicion?
- A. /var/log/daemon.log
- B. /var/log/ltm
- C. /var/log/kern.log
- D. /var/log/audit
Answer: B
Explanation:
Comprehensive and Detailed Explanation From BIG-IP Administration Control Plane Administration documents: Although /var/log/ltm is primarily associated with Local Traffic Manager events, it is also the primary destination for system-level alerts generated by the Control Plane's chmand (Chassis Manager Daemon). Hardware status changes, including power supply failures, fan speeds, and temperature warnings, are logged as "notice" or "critical" events within the LTM log file.
NEW QUESTION # 41
A BIG-IP Administrator needs to update the list of configured NTP servers. In which area of the Configuration Utility should the BIG-IP Administrator perform this update?
- A. System > Configuration
- B. System > Services
- C. System > Preferences
- D. System > Platform
Answer: A
Explanation:
NTP (Network Time Protocol) is vital for management connectivity and HA state synchronization. Correct time is required for log timestamping and device trust group communication46. To manage these settings, the administrator navigates to System > Configuration, where general system-level services like NTP and DNS are defined to ensure the Control Plane remains synchronized with the network environment.
NEW QUESTION # 42
An organization is performing a major release upgrade to its BIG-IP system. The system is under medium load and has enough disk space to perform the upgrade. Which pre-upgrade task is disruptive to regular system performance and should be performed during a maintenance window? (Choose one answer)
- A. Reactivate the license
- B. tmsh save sys config
- C. Create a QKView
- D. Generate a UCS
Answer: A
NEW QUESTION # 43
A BIG-IP Administrator defines a device Self IP. The Self IP is NOT reachable from the network. What should the administrator verify first?
- A. The correct Trunk has been selected.
- B. Verify if auto last hop is disabled.
- C. The correct VLAN has been selected.
- D. The correct Interface has been selected.
Answer: C
Explanation:
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.
NEW QUESTION # 44
A BIG-IP Administrator is setting up a new BIG-IP device. The network administrator reports that the interface has an incompatible media speed. The BIG-IP Administrator needs to change this setting manually. From which location should the BIG-IP Administrator perform this task?14
- A. In the Configuration Utility, System > Configuration18
- B. In the Configuration Utility, Network > Interface17
- C. On the Front Console15
- D. In the TMOS Shell Command line16
Answer: B
Explanation:
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.
NEW QUESTION # 45
A BIG-IP Administrator needs to restore an encrypted UCS archive from the command line using the TMSH utility. Which TMSH command should the BIG-IP Administrator use to accomplish this?
- A. load /sys ucs <filepath> no-license
- B. load /sys config file <filepath> passphrase <password>
- C. load /sys ucs <filepath> passphrase <password>
- D. load /sys config file <filepath>
Answer: C
Explanation:
Restoring system states from backups is a fundamental Control Plane administrative task2. When a User Configuration Set (UCS) archive is created with encryption, it requires the correct passphrase to be decrypted and loaded during the restoration process.
* UCS Command Structure: The tmsh load /sys ucs command is the specific utility for restoring these comprehensive configuration archives.
* Encrypted Restores: If the archive was encrypted during creation, the passphrase argument must be appended to the command followed by the actual password used to encrypt the file.
* Comparison with Other Options:
* load /sys config file is used for loading text-based configuration files (like bigip.conf), not full UCS archives6.
* The no-license flag is used when you want to restore a configuration without overwriting the existing license (common during RMA replacements), but it does not provide the mechanism for entering an encryption passphrase.
NEW QUESTION # 46
A configuration change is made on the standby member of a device group. What is displayed as
"Recommended Action" on the Device Management Overview screen?
- A. Activate device with the most recent configuration
- B. Force active member of device group to standby
- C. Synchronize the standby member configuration to the group
- D. Synchronize the active member configuration to the group.
Answer: C
Explanation:
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
NEW QUESTION # 47
One of the two members of a device group has been decommissioned. The BIG-IP Administrator tries to delete the device group, but is unsuccessful. Prior to removing the device group, which action should be performed? (Choose one answer)
- A. Make sure all members of the device group are in sync
- B. Disable the device group
- C. Remove all members from the device group
- D. Remove the decommissioned device from the device group
Answer: D
Explanation:
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.
NEW QUESTION # 48
A BIG-IP Administrator must determine if a Virtual Address is configured to fail over to the standby member of a device group. In which area of the Configuration Utility can this be confirmed?
- A. Device Management > Devices34
- B. Device Management > Overview36
- C. Local Traffic > Virtual Servers35
- D. Device Management > Traffic Groups
Answer: C
Explanation:
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.
NEW QUESTION # 49
A BIG-IP Administrator reviews the Plane CPU Usage performance chart and discovers a high percentage of Control Plane utilization. Which type of traffic does this indicate a higher usage of?
- A. Accelerated
- B. Tunnel
- C. Administrative
- D. Application
Answer: C
Explanation:
F5 architecture distinguishes between the Data Plane (TMM processing application traffic) and the Control Plane (Linux host processing management tasks). High Control Plane CPU utilization typically points to administrative activities such as heavy GUI usage, complex API calls (iControl), large-scale configuration synchronizations, or intensive logging/monitoring tasks rather than the actual switching or load balancing of application data.
NEW QUESTION # 50
Which log file should the BIG-IP Administrator check to determine if a specific user tried to log in to the BIG-IP Configuration Utility? (Choose one answer)
- A. /var/log/ltm
- B. /var/log/pam/tallylog
- C. /var/log/httpd
- D. /var/log/secure
Answer: D
Explanation:
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
NEW QUESTION # 51
Which interface is used for out-of-band management?
- A. VLAN interface
- B. Floating IP
- C. Management interface
- D. Self IP
Answer: C
Explanation:
The dedicated management interface is used for administrative access.
NEW QUESTION # 52
Which feature ensures configuration consistency between devices?
- A. Route domains
- B. VLAN tagging
- C. SNAT
- D. Device Service Clustering (DSC)
Answer: D
Explanation:
DSC enables config sync and failover between BIG-IP devices.
NEW QUESTION # 53
Refer to the output.
Color green
Status In Sync
Summary
Details
/Common/host1.company.com: connected (for 2548 seconds)
/Common/sync-fail-test (In Sync):
- all 2 devices consistent
/Common/device_trust_group (In Sync):
- all 2 devices consistent
Which TMSH command generated this output?
- A. tmsh show /sys sync-status
- B. tmsh list /sys sync-status
- C. tmsh list /cm sync-status
- D. tmsh show /cm sync-status
Answer: D
Explanation:
The correct command is tmsh show /cm sync-status because the displayed output is operational synchronization status, not configuration data. In TMSH, show is used to display runtime or current operational state, while list is used to display saved configuration objects and configured properties. The output contains status fields such as Color , Status , Summary , and Details , showing that the BIG-IP device is In Sync and that both the sync-fail-test device group and device trust group have all devices consistent.
This is live ConfigSync/device-group state information under the configuration management module /cm .
Therefore, the command that generates this status output is tmsh show /cm sync-status . Option A is incorrect because tmsh list /cm sync-status would attempt to list configuration, not display the operational sync status shown in the exhibit.
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NEW QUESTION # 54
A user needs to generate a QKView to upload to iHealth to determine any issues with upgrading TMOS. Where can the user generate the QKView in the Configuration Utility?
- A. System > Support
- B. System > Archives
- C. System > Configuration
- D. System > Software Management
Answer: A
Explanation:
Comprehensive and Detailed Explanation From BIG-IP Administration Control Plane Administration documents: Generating a QKView is a standard procedure for identifying device health and upgrade readiness42. Within the Configuration Utility, this Control Plane diagnostic tool is located under System > Support43. This utility collects configuration and state data into a single file used by the iHealth 'Upgrade Advisor' to report on known bugs or compatibility issues prior to a version change.
NEW QUESTION # 55
A BIG-IP Administrator needs to load a UCS file but must exclude the license file.
How should the administrator perform this task? (Choose one answer)
- A. From the CLI with command tmsh load /sys ucs <ucs filename> no-license
- B. From the GUI, select the UCS file, uncheck the license box, and click Restore
- C. From the CLI with command tmsh load /sys ucs <ucs filename>
- D. From the GUI, select the UCS file and click Restore
Answer: A
Explanation:
Comprehensive and Detailed Explanation From BIG-IP Administration Control Plane Administration documents:
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 <ucs filename> 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.
NEW QUESTION # 56
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