F5CAB1 Questions and Answers

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 understand:

Which modules arelicensed

Which modules areprovisioned

Theresource requirements(CPU / RAM) of each module

The administrator uses:

System » Resource Provisioning

This page displays:

All modules present in the license

Whether they are enabled or disabled

Required memory to activate each module

CPU and disk allocation information

Provisioning level options (None / Minimal / Nominal / Dedicated)

This is the exact location where BIG-IP administrators evaluate module capacity before enabling or purchasing licensing upgrades.

Why the other options are incorrect:

A. Configuration » OVSDB

Used for network virtualization integrations, not licenses or modules.

B. Software Management

Used for software image installation, not licensing.

C. Configuration » Device

Displays hostname, failover settings, device properties — not module resource requirements.

Thus, module licensing and memory requirement data are found underResource Provisioning.

The exhibit shows aSelf IPwith:

VLAN:Data

Port Lockdown:Allow None

Impact of “Allow None” on SNMP

When a Self IP is configured with:

Port Lockdown: Allow None

the BIG-IP blocksallservices and ports except a few hardcoded HA communication ports.

This means:

UDP/161 (SNMP)is blocked

UDP/162 (SNMP traps)is blocked

The SNMP server cannot poll or receive data from the BIG-IP through this Self IP

SNMP relies on access through the Self IP if out-of-band (mgmt interface) is not used.

Thus, the issue is directly caused byPort Lockdown = Allow None, which prevents SNMP communication.

Why the other options are incorrect:

B. Traffic Group must use a floating Traffic Group

SNMP polling doesnotrequire floating Self IPs.

Floating groups apply to HA failover IPs, not SNMP functionality.

C. VLAN/Tunnel must allow All VLANs

Self IPs are always bound to a VLAN; SNMP doesnotrequire All VLANs.

As long as the Self IP belongs to a reachable VLAN, SNMP can work.

D. Configuration is correct

It is not correct:Allow Noneblocks SNMP and is the problem.

BIG-IP hardware platforms use chassis LEDs to indicate system health states.

Asolid yellow status LEDtypically indicates awarning condition, such as:

A non-critical hardware alert

A temperature threshold nearing limit

A minor fan or sensor irregularity

Other non-fatal environmental or system conditions

This state reflects awarning-level alarm, meaning the unit is operational but requires investigation.

Why the other options are incorrect

A. Halted or EUD mode

This is associated with different LED patterns (usually flashing conditions or specific color codes), not a solid yellow status LED.

B. Standby in device group

HA state is not indicated by the chassis status LED.

Standby status is alogicaldevice state, not a hardware LED state.

D. Power supply failure

Power supply indicators use separate LEDs located on each power module (usually flashing amber/red), not the system status LED.

Thus, asolid yellow status indicatorsignifies awarning-level alarm.

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.

License reactivation updates the BIG-IP device’s license file to ensure:

TheService Check Dateis current

The device is eligible to install the intended TMOS version

Any module entitlement updates are received

Reactivationdoes not interrupt trafficand does not require a reboot, making it safe to performbeforethe maintenance window.

F5 best practices state:

Performall non-impact tasks priorto the scheduled maintenance window

Leave the window available for activities that require rebooting, such as the software installation itself

Since license reactivation isnon-disruptive, it should be donebeforethe upgrade window starts.

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.