PCNSA Practice Exam 3 — 20 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

Question 11

An organization wants to prevent data exfiltration via DNS tunneling. Which security profile should be applied to the outbound DNS traffic?

Accepted Answer

DNS Security profile. DNS Security profile is specifically designed to detect and block DNS tunneling, which is a technique used to exfiltrate data by encoding it within DNS queries and responses. By inspecting DNS traffic for anomalies such as high query rates, unusual domain names, or non-standard record types, the DNS Security profile can identify and prevent data exfiltration attempts. Other security profiles do not have the specialized DNS-layer inspection capabilities required to counter this threat.

Answer

Vulnerability Protection profile

Answer

URL Filtering profile

Answer

Anti-Spyware profile

Question 12

An administrator needs to generate a report showing all applications used by a specific user group over the past week. Which method is most efficient?

Accepted Answer

Use the ACC (Application Command Center) and filter by user group and time range. The ACC (Application Command Center) is purpose-built for rapid application visibility and analysis. By filtering by user group and time range directly within the ACC, the administrator can instantly see the top applications used by that group without exporting or manually parsing logs, making it the most efficient method for this specific reporting need.

Answer

Export Traffic logs to CSV and analyze in Excel

Answer

Use the Top Applications report in the Reports tab

Answer

Use the Monitor tab's Session Browser with a filter for the user group

Question 13

Which TWO of the following are valid methods to upgrade the PAN-OS version on a Palo Alto Networks firewall?

Accepted Answer

Using the GUI under Device > Dynamic Updates > Software. Option A is correct because the PAN-OS software upgrade can be initiated via the GUI under Device > Dynamic Updates > Software, where administrators can download and install new PAN-OS versions. This is a standard method for upgrading the firewall's operating system through the web interface.

Answer

Using the GUI under Device > Dynamic Updates > Content Updates

Answer

Downloading the image via SCP and using 'load software'

Answer

Using Panorama's 'Software' tab to push an upgrade to the firewall

Question 14

An administrator needs to back up the firewall configuration before making changes. Which method creates a complete backup that can be restored to the same or a different firewall?

Accepted Answer

Use the 'Device > Setup > Operations > Export named configuration snapshot' and select 'running-config.xml'. Option D is correct because exporting the running-config.xml via 'Device > Setup > Operations > Export named configuration snapshot' creates a complete XML backup of the entire running configuration. This file can be imported and restored to the same or a different firewall of the same model and PAN-OS version, ensuring full recovery of all settings, including network, policy, and object configurations.

Answer

Use the 'Device > Setup > Operations > Save named configuration snapshot' option

Answer

Use the 'Save Candidate Config' option in the GUI

Answer

Use the CLI command 'show config running' and copy the output

Question 15

When configuring a security policy rule to allow HTTP traffic from the internal zone to the external zone, which mandatory components must be defined?

Accepted Answer

Source Zone, Destination Zone, Source Address, Destination Address, Application, and Action. Option D is correct because a security policy rule in Palo Alto Networks firewalls requires at minimum the source zone, destination zone, source address, destination address, application, and action to be defined. For HTTP traffic from internal to external zones, these components ensure the rule is specific enough to match the intended traffic while leveraging App-ID for application identification, not just port-based service definitions.

Answer

Source Zone, Destination Zone, Application, and User

Answer

Source Zone, Destination Zone, Application, and Service

Answer

Source Zone, Destination Zone, Service, and Action

Question 16

An administrator needs to allow inbound SMTP traffic to a mail server located in the DMZ. The firewall has a public IP address on the external interface. Which configuration is necessary to ensure the mail server receives the traffic?

Accepted Answer

Configure a Destination NAT rule and a security policy rule allowing SMTP from external to DMZ.. To allow inbound SMTP traffic from the internet to a mail server in the DMZ, the firewall must perform Destination NAT (DNAT) to translate the public IP address on the external interface to the private IP address of the mail server. A corresponding security policy rule must permit SMTP (TCP port 25) traffic from the external zone to the DMZ zone. Without DNAT, the firewall would not know which internal server should receive the traffic, and without the security rule, the traffic would be blocked.

Answer

Configure a Source NAT rule to translate the mail server's IP to the public IP.

Answer

Configure a security policy rule with source NAT to translate the public IP to the private IP.

Answer

Configure a security policy rule allowing SMTP from external to DMZ without NAT.

Question 17

An organization is deploying a Palo Alto Networks firewall in a data center with multiple virtual routers. The network team wants to ensure that traffic between two different virtual routers can be inspected by the firewall. Which configuration is required?

Accepted Answer

Create a Security policy rule that allows traffic between the virtual routers.. Option D is correct because traffic between virtual routers must be explicitly permitted by a Security policy rule. Even though virtual routers provide separate routing tables, the firewall still enforces policy enforcement points; without a Security rule allowing the traffic, it will be denied by default. This ensures that inter-virtual-router traffic is inspected and controlled by the firewall's security engine.

Answer

Install a virtual wire between the virtual routers.

Answer

Add static routes for the remote subnets in each virtual router.

Answer

Configure a default route in each virtual router pointing to the other.

Question 18

A company uses App-ID to control cloud storage applications. Users report that uploads to Google Drive are blocked even though a rule allows 'google-drive-base'. What is the most likely cause?

Accepted Answer

The rule allows only 'google-drive-base' but the uploads use 'google-drive-upload'.. App-ID uses multiple application signatures to identify different functions within an application. 'google-drive-base' covers basic Google Drive traffic, but uploads are typically identified by a separate application signature, 'google-drive-upload'. Since the rule only allows 'google-drive-base', the firewall blocks the upload traffic because it does not match the permitted application. This is a common scenario where granular App-ID signatures must be explicitly allowed for specific actions like uploads.

Answer

The firewall is not connected to the cloud for App-ID updates.

Answer

Decryption is not enabled for Google Drive traffic.

Answer

An application override is configured for Google Drive.

Question 19

A security team notices that custom application 'myapp' is not being identified by App-ID even though the correct application override is in place. What should they verify first?

Accepted Answer

Verify that the traffic reaches the firewall and is allowed by a security policy rule that has App-ID enabled.. Option D is correct because App-ID identification occurs after the firewall receives traffic and matches a security policy rule. Even with a correct application override, the traffic must first be allowed by a security policy rule that has App-ID enabled; otherwise, the override is never evaluated. The override only applies to the application identification process, not to the policy enforcement layer.

Answer

Ensure the application uses a standard port.

Answer

Ensure SSL decryption is enabled for the application.

Answer

Check if the application override is applied to the correct rule.

Question 20

Which two components are part of Content-ID? (Choose two.)

Accepted Answer

File Blocking. File Blocking (option B) is a core component of Content-ID that allows administrators to block or allow specific file types based on MIME type or file extension, regardless of the application or port used. Data Filtering (option C) is also part of Content-ID and enables inspection of data patterns (e.g., credit card numbers, SSNs) within application traffic to prevent data exfiltration. Both features operate after App-ID identifies the application, providing granular control over content within allowed sessions.

Answer

Application Override

Answer

URL Filtering