F5 Updated F5CAB1 Exam Questions and Answers by izabela

When a TMOS ISO file is transferred to /shared/images/ , the BIG-IP automatically performs a validation step:

Checksum Verification

Before the image becomes visible in the GUI, the system verifies the internal checksum embedded inside the ISO.

This ensures:

The file was fully transferred

The image is not corrupted

It matches the official F5 release signature

Only after passing this verification does the GUI display the ISO under “Available Images.”

Why the other options are incorrect:

A. Reboot into a new partition

No reboot occurs simply from uploading an image.

C. Copying into /var/local/images/

This directory is not used for ISO storage.

All valid images remain in /shared/images/ .

Thus, the correct system action is checksum verification .

The exhibit shows a Self IP with:

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 blocks all services 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 by Port Lockdown = Allow None , which prevents SNMP communication.

Why the other options are incorrect:

B. Traffic Group must use a floating Traffic Group

SNMP polling does not require 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 does not require 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 None blocks SNMP and is the problem.

The screenshot shown is from the User Administration section of the BIG-IP GUI.

This section controls:

Root and Admin passwords

SSH Access

SSH IP Allow settings

However, it does not contain any controls for restricting access to the WebUI (TMUI) .

BIG-IP does not provide TMUI access restrictions from this part of the GUI.

Access to the web-based Configuration Utility is controlled by the httpd allow list , configured through TMSH:

tmsh modify /sys httpd allow { < IP/subnet > }

This setting is not displayed in the User Administration panel, and in many BIG-IP versions, the httpd allow list is only configurable from the CLI , not the GUI.

Therefore, the administrator cannot find the setting in the screen shown because:

TMUI access restriction is not located in this GUI section

It must be configured using tmsh under /sys httpd allow

This is why Option A is correct.

Comprehensive and Detailed Explanation From BIG-IP Administration — Install, Initial Configuration, and Upgrade:

The Service Check Date embedded in the BIG-IP license acts as a gating mechanism that determines eligibility for software updates. F5 enforces that the Service Check Date must be equal to or newer than the software release date of any BIG-IP version being installed. If the installed license carries a Service Check Date from two years ago, attempting to upgrade to a newly released BIG-IP software version — whose release date post-dates that Service Check Date — will fail, as the system validates this date during the upgrade process.

Option A is incorrect — generating and uploading a QkView to F5 iHealth is a diagnostic activity that requires no license validation or Service Check Date verification whatsoever.

Option C is incorrect — ASM signature and threat campaign updates are content updates, not platform software upgrades. These updates are independent of the Service Check Date requirement and do not trigger license validation checks during installation.

Only a platform software upgrade to a newly released BIG-IP version directly invokes the Service Check Date validation, mandating license renewal prior to the upgrade proceeding successfully.

Reference Topics: License Service Check Date, Software Upgrade Prerequisites, License Reactivation — BIG-IP Administration Study Guide.