F5 F5CAB1 Dumps Questions Answers

Port Lockdown controls which ports and protocols aSelf IPwill respond to.

However, certain traffic types bypass Port Lockdown for BIG-IP functionality and routing integrity.

The three types that areNOT affectedby Port Lockdown are:

1. Defined Virtual Server Traffic

Traffic destined to a Self IP that matches aconfigured virtual serveris always accepted by the BIG-IP, regardless of Port Lockdown settings.

This ensures that traffic processing does not break when administrators restrict Self-IP ports.

2. ICMP (Internet Control Message Protocol)

ICMP (such as ping, traceroute responses, etc.) always passes through a Self IP even when Port Lockdown is set to:

Allow Default

Allow None

Allow Custom

F5 allows ICMP for reachability and diagnostic purposes independent of Port Lockdown rules.

3. Centralized Management Infrastructure (CMI)

CMI includes the internal HA services used for:

Device Trust

ConfigSync

Failover

Mirroring

These essential HA communications bypass Port Lockdown to prevent accidental cluster failure.

The well-known port for this traffic isTCP 4353, which is always permitted.

Why the other options are incorrect:

Option A:SSHisrestricted by Port Lockdown unless explicitly allowed.

Option B:Same issue — SSH does not bypass Port Lockdown.

OnlyDefined VS Traffic,ICMP, andCMIbypass Port Lockdown.

BIG-IP allocates CPU and memory resources based on module provisioning levels.

To view how much CPU a module is assigned, administrators must check provisioning information from:

C. GUI — System » Resource Provisioning

This page visually displays CPU allocation via color-coded bars.

Hovering over the CPU bar shows:

CPU usage percent per module

Which modules share CPU cycles

The system’s total resource allocation

This is the primary GUI method.

D. tmsh show /sys provision

This command displays detailed module provisioning information including:

Provisioned modules

Their provisioning level

CPU and memory allocation data

It is the authoritative CLI method for resource provisioning status.

Why the other options are incorrect:

A. top

Shows real-time process usage, notprovisionedCPU allocation.

B. tmsh show /sys cpu

Displays CPU runtime utilization, not per-module provisioning.

E. Statistics Dashboard

Only shows traffic / system runtime metrics, not provisioning resource allocations.

Therefore,C and Dare correct.

The exhibit shows the configuration of aSelf IPwith:

Port Lockdown: Allow Custom

ACustom Listthat includes the following TCP ports:

443

22

Meaning of these ports:

TCP 443→ HTTPS (TMUI — web-based management)

TCP 22→ SSH (command-line remote access)

No other TCP, UDP, or protocol entries are listed; therefore, only these two services are allowed to reach the BIG-IP via this Self IP.

Evaluating the answer choices:

Option

Service

Port

Allowed?

FTP

TCP 21

Not listed

Not allowed

SSH

TCP 22

Listed

Allowed

Telnet

TCP 23

Not listed

Not allowed

Thus,SSHis the only traffic permitted through this Self IP configuration.