PCNSA Practice Test 5 — 10 Questions

Question 1

A firewall administrator notices that a security rule intended to block traffic from a specific IP address is not working. The rule is placed at the bottom of the security rulebase, and the traffic is being allowed by a rule higher in the list. What is the most likely cause?

Accepted Answer

The rule is positioned below an allow rule that matches the same traffic.. Option C is correct because the Palo Alto Networks firewall evaluates security rules in top-down order, from the first rule in the rulebase to the last. If a rule that allows traffic is placed higher in the list, it will match and permit the traffic before the lower-placed block rule is ever evaluated. The block rule at the bottom is effectively never reached for that traffic, which is why the intended blocking action fails.

Answer

The source IP is negated in the rule.

Answer

The rule is placed at the top of the rulebase and overridden by a later rule.

Answer

The rule is disabled in the rulebase.

Question 2

An organization has a security policy that requires all outbound HTTP traffic from the 'Corporate' zone to the 'Internet' zone to be inspected by the URL Filtering profile. However, the administrator notices that some users can still access blocked categories. What is the most likely cause?

Accepted Answer

The URL Filtering profile is set to 'alert' instead of 'block' for the relevant categories.. Option D is correct because if the URL Filtering profile is set to 'alert' instead of 'block' for the relevant categories, the firewall will log the violation but still allow the traffic to pass. This means users can access blocked categories even though the rule is correctly applied, as the profile does not enforce a blocking action.

Answer

The firewall is configured to use DNS sinkholing, which bypasses URL filtering.

Answer

The rule is placed too low in the rulebase and a higher rule allows traffic without URL filtering.

Answer

The rule uses a source zone of 'Corporate' but the users are in a different zone.

Question 3

Which THREE factors should be considered when troubleshooting a 'deny' rule that is unexpectedly blocking traffic? (Choose three.)

Accepted Answer

The position of the deny rule in the rulebase relative to allow rules.. Option A is correct because the firewall evaluates rules in top-down order, and a deny rule placed above an allow rule for the same traffic will match first and block the traffic, even if a subsequent allow rule would have permitted it. This is a fundamental aspect of policy evaluation in Palo Alto Networks firewalls, where the first matching rule is applied and no further rule processing occurs.

Answer

Whether logging is enabled on the rule.

Answer

Whether SSL decryption is enabled for the traffic.

Question 4

During a firewall upgrade from PAN-OS 9.1 to 10.0, the administrator receives an error that the upgrade cannot proceed because there is a pending commit. The administrator checks the commit status and sees that a commit was initiated but has not completed. What is the best course of action?

Accepted Answer

Run 'commit force yes' from the CLI to force the commit. Option B is correct because the 'commit force yes' command overrides a stuck or incomplete commit by forcing the commit operation to proceed, which clears the pending commit state and allows the upgrade to continue. In PAN-OS, a pending commit blocks administrative operations like upgrades, and forcing the commit is the safest way to resolve this without disrupting the firewall's operational state.

Answer

Reboot the firewall to clear the pending commit

Answer

Wait for the commit to complete automatically

Answer

Cancel the upgrade and restart

Question 5

A network engineer wants to configure a new VLAN interface on a Palo Alto Networks firewall. After creating the VLAN object and assigning it to an Ethernet interface, the VLAN interface remains down. What is the most likely cause?

Accepted Answer

The Ethernet interface is not set to layer 2 mode or the VLAN tag is not allowed. For a VLAN interface to be operational on a Palo Alto Networks firewall, the underlying Ethernet interface must be configured in Layer 2 mode and the specific VLAN tag must be allowed on that interface. If the Ethernet interface remains in Layer 3 mode or the VLAN tag is not included in the allowed list, the VLAN interface will remain administratively down, as it cannot associate with a physical port that is not set to accept VLAN traffic.

Answer

The VLAN interface needs an IP address configured

Answer

The VLAN interface must be assigned to a virtual router

Answer

The firewall needs a commit to apply the changes

Question 6

Which THREE of the following are valid steps when configuring a new virtual wire (vwire) on a Palo Alto Networks firewall?

Accepted Answer

Add two or more interfaces as members of the virtual wire. Option A is correct because a virtual wire requires at least two interfaces to be added as members, which allows the firewall to transparently bridge traffic between them without any IP configuration. The virtual wire acts as a Layer 2 bump-in-the-wire, so interfaces are placed into the vwire to forward frames based on MAC addresses, not IP routing.

Answer

Assign an IP address to the virtual wire

Answer

Create a security policy allowing traffic on the virtual wire

Question 7

A security administrator notices that a user's traffic is being blocked unexpectedly. The user's IP is 10.1.1.100, and the traffic is destined to a web server at 192.168.2.10. The administrator has already verified that there are no security rules explicitly denying the traffic. Which Log Viewer query should the administrator use to quickly identify the cause?

Accepted Answer

Search Traffic logs with filters for source 10.1.1.100 and destination 192.168.2.10. Traffic logs capture every session that passes through the firewall, including allowed and denied connections. By filtering for the specific source IP (10.1.1.100) and destination IP (192.168.2.10), the administrator can quickly see the exact session details, including the action taken (e.g., deny, drop) and the reason (e.g., no matching rule, application override). This is the most direct method to identify why traffic is being blocked when no explicit deny rule exists.

Answer

Search Threat logs for the destination IP

Answer

Search Config logs for any rule changes

Answer

Search System logs for the user's IP

Question 8

Which TWO of the following are valid methods to collect a technical support file from a Palo Alto Networks firewall?

Accepted Answer

Using the GUI under Device > Troubleshooting > Generate Tech Support File. Option C is correct because the Palo Alto Networks firewall GUI provides a dedicated path under Device > Troubleshooting > Generate Tech Support File to generate and download a comprehensive technical support file. This file bundles logs, configuration, and system state data essential for troubleshooting.

Answer

Using the CLI command 'save config to tftp'

Answer

Using the GUI under Monitor > Packet Capture

Answer

Using the CLI command 'show tech-support'

Question 9

A company wants to deploy a new firewall with a management interface on a separate VLAN to ensure management traffic is isolated from production traffic. Which interface type should be used for management access?

Accepted Answer

MGT (Management) interface. The MGT (Management) interface is a dedicated physical port on Palo Alto Networks firewalls designed specifically for out-of-band management traffic. It operates on a separate routing table and does not participate in production data forwarding, ensuring complete isolation of management traffic from production traffic as required by the scenario.

Answer

HA1 interface

Answer

VLAN interface

Answer

Ethernet 1/1

Question 10

A security analyst notices that a legitimate application is being incorrectly identified as a different application by the firewall. What is the best first step to resolve this issue?

Accepted Answer

Verify the application signature in the App-ID database and submit a false-positive report if needed. Option C is correct because the first step in resolving an application misidentification is to verify the application signature in the App-ID database. If the signature is incorrect or missing, submitting a false-positive report allows Palo Alto Networks to update the database, ensuring accurate identification without manual overrides. This aligns with the principle of using the built-in App-ID engine as the primary identification method.

Answer

Reboot the firewall to refresh the application cache

Answer

Disable the application override and use port-based rules

Answer

Create a custom App-ID to override the incorrect identification