PCNSA Practice Test 14 — 15 Questions

Question 1

A security administrator needs to create address objects for a group of servers that share the same subnet 192.168.10.0/24. Which TWO methods can be used to efficiently manage these objects in Palo Alto Networks firewall configuration?

Accepted Answer

Create a single address object with IP subnet 192.168.10.0/24.. Option C directly uses the subnet as an address object, which is efficient for a contiguous subnet. Option D uses a dynamic address group with tags, allowing flexible grouping without manual updates. Option A uses a range, which is less efficient for a subnet. Option B requires creating multiple individual objects. Option E is not a valid concept.

Answer

Create an address group and add individual address objects for each server IP.

Answer

Create a single address object with IP range 192.168.10.1-192.168.10.254.

Answer

Create a predefined address object from the global cache.

Question 2

Refer to the exhibit. A network administrator sees this output from a Palo Alto Networks firewall. What does the 'System mode: virtual' indicate about this firewall?

Accepted Answer

It is a VM series firewall running on a hypervisor.. The 'System mode: virtual' output indicates the firewall is a VM-Series instance running on a hypervisor such as VMware ESXi, KVM, or Hyper-V. This mode is distinct from physical appliances and cloud-native instances, as it leverages virtualized hardware resources while maintaining full PAN-OS functionality.

Answer

It is a physical firewall configured in high availability active-active mode.

Answer

It is a Panorama management server.

Answer

It is a cloud-based firewall instance (e.g., AWS, Azure).

Question 3

What is the primary benefit of using App-ID in a security policy instead of relying solely on port-based rules?

Accepted Answer

It allows enforcement based on application identity, even if the application uses non-standard ports.. Option C is correct because App-ID identifies the actual application regardless of port, allowing policy enforcement based on application identity. Option A is wrong because App-ID does not simplify rule management by itself. Option B is wrong because performance may be marginally impacted. Option D is wrong because App-ID is not only for HTTP traffic.

Answer

It increases firewall throughput.

Answer

It reduces the number of security rules needed.

Answer

It limits traffic to HTTP and HTTPS only.

Question 4

A large university uses a Palo Alto Networks firewall to secure its network. The security team has implemented a policy to block peer-to-peer (P2P) file sharing applications. They have configured a security rule that denies all applications in the 'peer-to-peer' category. However, they notice that some students are still able to download files using BitTorrent. The traffic logs show the application as 'bittorrent' but the rule does not match. Upon investigation, the rule is applied to the correct zones and includes the peer-to-peer category. The source and destination are any. What is the most likely cause of this issue?

Accepted Answer

The rule is placed after an allow rule that matches the traffic.. Option D is correct because in Palo Alto Networks firewalls, security rules are evaluated in order from top to bottom. If a rule that allows traffic (e.g., a broad allow rule) is placed before the deny rule for peer-to-peer applications, the traffic will match the allow rule first and be permitted, never reaching the deny rule. This is a common misconfiguration where rule ordering overrides the intended policy, even when the deny rule is correctly configured with the peer-to-peer category.

Answer

BitTorrent is not part of the peer-to-peer application category.

Answer

The security rule is using an application group instead of an application filter.

Answer

The firewall does not have the latest App-ID update and cannot identify BitTorrent.

Question 5

Which Content-ID feature can be used to prevent data loss by blocking specific patterns in traffic?

Accepted Answer

Data Filtering. Data Filtering is the correct answer because it is the Content-ID feature specifically designed to inspect application-layer traffic for predefined patterns, such as credit card numbers, social security numbers, or custom regex patterns, and block or alert on matches to prevent data loss. Unlike URL Filtering or File Blocking, Data Filtering operates on the content within allowed traffic, making it the direct tool for data loss prevention (DLP) based on pattern matching.

Answer

URL Filtering

Answer

File Blocking

Answer

WildFire

Question 6

An administrator is troubleshooting why an application is being identified as 'incomplete' in the traffic log. What does this indicate?

Accepted Answer

The session was terminated before App-ID could complete.. When App-ID cannot complete its analysis before the session terminates, the traffic log marks the application as 'incomplete'. This typically happens with short-lived sessions or when the firewall receives insufficient data packets to match a signature or decode the protocol. The correct answer is B because App-ID requires multiple packets or a full handshake to definitively identify the application.

Answer

The application is using a non-standard port.

Answer

The firewall could not determine the application.

Answer

The application is unknown to the firewall.

Question 7

During an App-ID upgrade, some applications are no longer identified correctly. What is the most likely cause?

Accepted Answer

The custom application signatures were not migrated.. During an App-ID upgrade, custom application signatures are stored separately from the built-in application database. If these custom signatures are not migrated to the new version, the firewall will lose the ability to identify those applications, even though the built-in App-ID database is updated. This is the most likely cause because the upgrade process does not automatically preserve user-defined objects.

Answer

The security rules were modified.

Answer

The application database was rolled back.

Answer

The firewall needs a reboot.

Question 8

An administrator wants to block all peer-to-peer file sharing traffic, but must ensure that legitimate business applications like FTP are not affected. Which approach is most effective?

Accepted Answer

Create an Application Filter that matches all P2P applications and use it in a deny rule.. Option A is correct because Palo Alto Networks App-ID can identify peer-to-peer (P2P) traffic by application signature, regardless of port. Creating an Application Filter that matches all P2P applications (e.g., BitTorrent, eDonkey, Gnutella) and applying it in a deny rule ensures all P2P traffic is blocked while legitimate business applications like FTP (which uses distinct App-ID signatures) are not affected, as App-ID decodes traffic at Layer 7.

Answer

Create a security rule with 'application none' and block the common P2P ports.

Answer

Use a Service object to block all ports typically used by P2P applications.

Answer

Identify each known P2P application and add them individually to a block rule.

Question 9

During a security audit, it is discovered that some users are bypassing the company's web proxy by using HTTPS to external websites. The firewall is configured to allow 'web-browsing' application. What is the best way to enforce proxy usage for all HTTP/HTTPS traffic?

Accepted Answer

Create a security rule that denies 'web-browsing' from users to the internet, and a separate rule allowing only the proxy server to use web-browsing.. Option A is correct because by blocking the 'web-browsing' application directly, users cannot bypass the proxy; only the proxy server should be allowed to use web-browsing. Option B is wrong because SSL decryption does not enforce proxy usage. Option C is wrong because URL filtering can block categories but does not enforce proxy. Option D is wrong because App-ID and Content-ID work together, but the key is to control the application.

Answer

Enable SSL decryption and block traffic that is not decrypted.

Answer

Configure Content-ID to block all web traffic.

Answer

Use URL filtering to block all URLs except those from the proxy.

Question 10

A security engineer wants to block downloading of executable files over HTTP and HTTPS, but allow all other web traffic. Which Content-ID feature should be configured to achieve this granular control?

Accepted Answer

Set up a File Blocking Profile and apply it to the security rule for web-browsing.. Option D is correct because a File Blocking Profile is specifically designed to block the transfer of files based on file type (e.g., PE executables) over any allowed application, such as web-browsing. By applying this profile to a security rule that permits HTTP and HTTPS traffic, you can block executable downloads while allowing all other web content. This leverages Content-ID's file-type identification, which inspects the actual file content (magic bytes) rather than relying on extensions or application signatures.

Answer

Use an Application Override to identify executables.

Answer

Create a Data Filtering Profile to block executable file types.

Answer

Configure a URL Filtering Profile to block executables.

Question 11

Which TWO statements about App-ID are correct? (Choose two.)

Accepted Answer

App-ID can identify applications even if they use standard ports for other services.. Option A is correct because App-ID uses multiple identification mechanisms—including application signatures, SSL/TLS fingerprinting, and behavioral analysis—to identify applications regardless of the port they use. This means an application like SSH running on TCP 443 (typically used for HTTPS) will still be correctly identified as SSH, not as web-browsing traffic.

Answer

App-ID is only effective for well-known commercial applications.

Answer

App-ID primarily identifies applications based on port numbers.

Answer

App-ID requires at least 10 packets to identify an application.

Question 12

Which THREE are valid components of Content-ID? (Choose three.)

Accepted Answer

URL Filtering. Options A, C, and D are correct because Content-ID includes URL Filtering, File Blocking, and Data Filtering. Option B is wrong because Application Override is part of App-ID, not Content-ID. Option E is wrong because Application Filters are part of App-ID.

Answer

Application Filters

Answer

Application Override

Question 13

Refer to the exhibit. A user on the Trust zone is trying to download a file from an FTP server on the Untrust zone using FTP on TCP port 21. The firewall's security policy is as shown. What will happen?

Accepted Answer

The traffic is denied by the 'Block-FTP' rule.. The correct answer is C because the security policy explicitly includes a rule named 'Block-FTP' that denies FTP traffic. FTP uses TCP port 21 for control traffic, and the firewall matches this traffic against the policy rules in order. Since 'Block-FTP' matches the FTP application (or port 21) and denies it, the traffic is blocked before reaching any implicit deny rule.

Answer

The traffic is denied by the implicit deny rule at the end.

Answer

The traffic is allowed because 'Allow-Web' matches web-browsing over port 80 or 443.

Answer

The traffic is allowed because no rule explicitly blocks it.

Question 14

During a security audit, it is discovered that FTP traffic over non-standard ports is bypassing App-ID inspection. What is the most effective method to ensure all FTP traffic is identified, regardless of port?

Accepted Answer

Create an Application Override rule for FTP on the required source and destination addresses.. Option A is correct because an Application Override for FTP can be configured to identify FTP traffic on any port by specifying the application and source/destination. Option B is wrong because disabling App-ID removes inspection. Option C is wrong because updating App-ID database does not change detection behavior for custom ports. Option D is wrong because Service definitions are port-based, not application-based.

Answer

Update the App-ID and threat databases to the latest version.

Answer

Set the security policy to 'allow' without App-ID to ensure FTP works.

Answer

Add the non-standard port to the FTP service definition.

Question 15

Refer to the exhibit. A user reports being unable to connect to a website over HTTPS. The traffic log shows the application as 'incomplete' and the rule 'Block-Unknown-App' is matched. What is the most likely reason the application is 'incomplete'?

Accepted Answer

App-ID has not yet completed identification because the session is new or requires more packets.. When a firewall logs an application as 'incomplete', it means App-ID has not yet finished identifying the application for that session. This typically occurs for new sessions or when the firewall needs to see more packets (e.g., the SSL/TLS handshake or additional data) to match a signature. Since the session matched a rule that blocks unknown applications, the firewall is correctly enforcing the policy while App-ID is still in progress.

Answer

The security rule is misconfigured because it lacks an application field.

Answer

The firewall does not have an App-ID signature for the website.

Answer

SSL decryption is not enabled, so App-ID cannot identify HTTPS traffic.