Free and Premium F5 F5CAB1 Dumps Questions Answers

The BIG-IPmanagement interface (MGMT port)is controlled throughSystem settings, not through the Network menu.

SSH access on the management interface is configured here:

System → Configuration → Device → General → SSH Access / SSH IP Allow

This section allows the administrator to:

Enable or disable SSH service

Restrict SSH access to specific IP addresses or subnets

Apply security policies to the management interface

Why the other options are incorrect:

A. Network > Interfaces

Used for data-plane physical interface settings, not management plane SSH restrictions.

B. Network > Self IPs

Controls in-band management or data-plane access, not the dedicated management port.

D. System > Platform

Used for hostname, time zone, LCD contrast, hardware settings — not SSH security on the management port.

Therefore, restricting SSH access to themanagement interfacemust be done under:

✔System → Configuration → Device → General

Which corresponds toOption C.

When you chooseAutomaticas the activation method in the License › Re-activate screen, the BIG-IP device itself contacts F5’slicense activation serviceover the Internet.

For successful automatic activation:

The BIG-IP must have outbound network connectivity (typically via the management interface).

DNS resolution and routing must allow it to reach theF5 license activation host(the one shown in option D).

The device sends its dossier and registration key to that service and receives an updated license file in return, which is then installed automatically.

The other hostnames in the options are not used by BIG-IP for license activation, so they cannot be correct in the context ofAutomatic Activation.

ThePort Lockdownfeature controls which services a Self-IP will respond to.

Setting a Self-IP toAllow Nonemeans:

The Self-IP will not acceptanytraffic except the very limited, hard-coded HA ports such asTCP 4353used for device trust and configuration sync.

All other HA ports, including those needed for network failover and other HA mechanisms,are blocked.

When essential HA services cannot communicate, each device assumes its peer is down.

This results in:

HA failover misbehavior

Both devices thinking the other is offline

Potentialactive-active condition, which is not intended and can cause traffic disruption

Thus,Allow Nonecan break HA functionality unless the Self-IP is not used for HA links.

When installing a software upgrade with a HotFix on BIG-IP, the correct workflow requires:

Install the base TMOS imageon an unused boot volume

Install the corresponding HotFixonto that same boot volume

Activate the updated boot volumeto boot into the new software

This method ensures:

The existing active system (HD1.1) is untouched

The upgrade occurs in a new, clean volume (HD1.2)

The HotFix applies properly to the same base image

The administrator can revert to HD1.1 if issues occur

OptionCmatches the correct F5 upgrade sequence:

1. Install base image on HD1.2

2. Install HotFix on HD1.2

3. Activate HD1.2

Why the other options are incorrect:

A. Install HotFix before base image

HotFixes must be appliedafterthe base image; not valid.

B. Installing a HotFix on the active boot location (HD1.1)

Not recommended and does not use a clean new volume.

Also does not involve installing the base image.

D. Activating HD1.2 before installing anything

Cannot activate an empty or invalid boot volume.

Thus,Option Cis the correct sequence.

Access to the BIG-IP Configuration Utility (TMUI) is controlled through the/sys httpd allowlist.

This list defines which IP addresses or subnets are allowed to connect to the management web interface.

To allow two new subnets—172.28.31.0/24and172.28.65.0/24—the administrator mustaddboth subnets to the existing list without removing current entries.

In tmsh, subnet entries must be specified innetwork/netmask format, for example:

172.28.31.0/255.255.255.0

The correct tmsh command to append these networks is:

modify /sys httpd allow add { 172.28.31.0/255.255.255.0 172.28.65.0/255.255.255.0 }

Why the other options are incorrect:

Option B:

IPs are listed without masks, which is invalid for subnet-based access control.

The system requiresnetwork/netmaskformat.

Option C:

The command uses permit instead of allow, which is not a valid attribute of /sys httpd.

The correct keyword must beallow.

Thus, onlyOption Acorrectly adds both permitted subnets in the proper tmsh format.

When installing a HotFix on a BIG-IP device, F5 best practices require:

Installing the base TMOS image on a new, unused boot volume (HD1.2)

This ensures the upgrade happens on a clean volume.

The existing active boot location remains untouched for rollback.

Installing the HotFix onto the SAME new boot volume (HD1.2)

HotFixes must be applied on top of a base version.

They cannot be installed on an empty volume.

They must match the base image version.

Activating the new boot volume (HD1.2)

The system reboots into the updated software stack.

Activation happensafterbase + HotFix installation is complete.

This sequence is exactly shown inOption C:

Install base Image in HD1.2

Install HotFix in HD1.2

Activate HD1.2

Why the other options are incorrect:

A. Install HotFix before base image

Impossible.

HotFix requires an installed base version first.

B. Installing HotFix on HD1.1 (active boot volume)

Not recommended.

Upgrading in-place removes rollback safety.

HotFix cannot be applied cleanly without applying base image first.

D. Activate HD1.2 before installing anything

You cannot activate an empty boot volume.

Activation only occurs after the base + HotFix software is installed.

When upgrading to a newer TMOS software version, BIG-IP validates whether the current license is permitted to run that version.

This is controlled by theService Check Datein the device’s license file.

If the Service Check Date is older than the minimum required for the target version:

The systemboots into the new volume,

Butfails to load the configuration,

And will instead present messages indicating that the configuration cannot be applied due to aninvalid or outdated license.

This is a well-known behavior:

An outdated license, not reactivated before upgrade, causes configuration load failure after reboot into the new software.

Why the other options are incorrect:

A. Performed on the standby unit

Upgrading a standby unit does not cause configuration load failure.

Standby-only upgrades are standard best practice.

C. Two reboots required

BIG-IP does not require two reboots during an upgrade.

One reboot into the new volume is sufficient.

D. DNS connectivity failure

DNS connectivity does not affect configuration loading.

DNS is only needed for automatic license activation, not for applying config at boot.

Thus, the configuration failed to load because thelicense was not reactivated before the upgrade, makingOption Bcorrect.

Securing the BIG-IP management interface is a fundamental administrative responsibility. F5 best practices emphasize restricting who can reach the management port and ensuring that only authorized systems are allowed access.

A. Limiting management access to trusted network segments

F5 recommends placing the management interface on adedicated, isolated, and secured management network or VLAN, rather than exposing it to production or untrusted networks.

This reduces the attack surface by ensuring only trusted segments have visibility to administrative interfaces.

D. Restricting management access by IP or subnet

F5 BIG-IP uses the/sys httpd allowlist (for HTTPS) and configuration options insshd(for SSH) to control which IP addresses or subnets can access the device.

By specifying only known administrative IPs or ranges, unauthorized users cannot reach the login services.

Why the other options are incorrect

B. Blocking all management HTTPS/SSH ports

This would prevent any administrative access and is not a viable security practice.

C. Using Self-IP addresses for administrative access

F5 explicitly warns against using Self-IPs for management access unless strictly necessary.

Self-IPs are exposed to the data plane and should not be used as the primary administrative interface.

The HTTPD allow list controls which IP addresses or subnets may access the Configuration Utility (TMUI) on the BIG-IP system. The Administrator already has two subnets allowed and needs to add asingle host IPto the existing list.

The object/sys httpd allowsupports actions such asadd,delete, andreplace-all-with.

Because the goal is toaddone more entry without removing the existing permitted subnets, the correct command is:

modify /sys httpd allow add { 172.28.32.22 }

This appends the new host to the existing list while preserving the previously configured networks.

Why the other options are incorrect:

Option A (replace-all-with)wouldoverwritethe entire allow list, removing existing permitted subnets—unacceptable.

Option B (delete)wouldremovethe existing networks and not add the required host.

Therefore, the correct administrative action is toaddthe jump host’s IP.

To change the boot volume on a BIG-IP system from one installed TMOS version to another, the correct CLI tool is:

switchboot

The correct syntax uses the-bflag:

switchboot -b

This command marks the specified boot location as the one to be used on the next reboot.

Thus, to boot intoHD1.2which contains13.1.0.6, the sequence is:

Mark HD1.2 as the next boot location:

switchboot -b HD1.2

Reboot the system:

reboot

This is the standard and officially supported method for selecting a different installed volume.

Why the other options are incorrect:

A. "tmsh reboot HD1.2"

There is no such tmsh syntax.

Boot volume cannot be selected by adding a parameter to reboot.

C. switchboot -I HD1.2

The -I flag is invalid. Only -b is used.

D. "tmsh switchboot HD1.2"

switchboot isnota tmsh command; it is a system-level shell utility.

Therefore,Option Bis the correct and valid command sequence.

In BIG-IP, software images are installed onboot volumes(for example, HD1.1, HD1.2, HD1.3, etc.).

To install software on anew volume, the administrator must instruct the system to create a new boot location before installation.

There are two correct ways to create a new volume:

A. tmsh command (with correct syntax)

tmsh install software image /shared/images/BIGIP-.iso volume HD1.5 create-volume

This syntax correctly includes:

install software image

full path to ISO (/shared/images/...)

volume name (HD1.5)

create-volumekeyword

This instructs BIG-IP to create the new boot volume as part of the installation.

C. Using the GUI → System > Disk Management

From the Disk Management menu, the administrator can:

Select “New Volume”

Enter the volume identifier (e.g., HD1.5)

Apply changes

This GUI method is officially supported and explicitly creates a new boot volume before installing the software.

Why the other options are incorrect:

B. Incorrect tmsh syntax

Missing /shared/images/ path

Incorrect command structure

D. Incorrect command structure

Missing required keywords and correct command hierarchy

E. Software Management → Install does NOT create volumes

This installs to anexistingvolume only

The GUI install dialog does not create new boot volumes

Thus, onlyOption AandOption Cproperly create a new software volume.

Provisioning settings define which modules are enabled and how system resources are allocated to them.

These provisioning declarations are stored in:

/config/bigip.conf

This file contains:

Full module provisioning statements

TMSH-equivalent provisioning configurations such as:

sys provision ltm { level nominal }

sys provision asm { level nominal }

It is theprimary system configuration filethat stores all active provisioning details.

Why the other answers are incorrect

A. /config/bigip.license

Showslicensedmodules, not provisioned modules.

B. /config/bigip_base.conf

Stores base networking (VLANs, Self-IPs, routes), not provisioning.

D. config.ucs

A backup archive, not a live configuration file.

Thus, the correct file to review active module provisioning is/config/bigip.conf.

When a TMOS image (.iso file) is uploaded into the/shared/images/directory, the BIG-IP performs an internal validation step before the ISO appears in the GUI.

1. The system verifies the internal checksum

BIG-IP automatically reads the embedded checksum inside the ISO file

Verifies integrity of the uploaded image

Confirms the file is not corrupted or incomplete

Ensures the image is a valid F5 TMOS software image

Only after this checksum verification succeeds does the image appear under:

System → Software Management → Image List

Why the other options are incorrect:

A. The system performs a reboot into a new partition

Uploading an ISO file never triggers a reboot.

C. The system copies the image to /var/local/images/

All valid TMOS images remain in/shared/images/.

No copying occurs.