PCNSE Practice Questions 2 — 50 Questions

Question 1

A network engineer wants to reduce the number of applications in security policies by combining several applications that are always used together. What is the best practice?

Accepted Answer

Configure an application group and add all related applications.. Using application groups simplifies policy management and ensures consistent policy for related applications. Option A is wrong because wildcard applications are too broad. Option B is wrong because creating a custom container application is not a standard feature. Option D is wrong because removing applications reduces visibility.

Answer

Use a wildcard application for the protocol.

Answer

Create a custom application that covers all the applications.

Answer

Remove the individual applications and just use port-based rules.

Question 2

A security architect needs to enforce authentication for all application-based policies using an external authentication source with MFA. Which combination of features best achieves this?

Accepted Answer

SAML authentication with an identity provider that supports MFA. B is correct because SAML authentication with an identity provider (IdP) that supports MFA allows the firewall to offload authentication to an external IdP, which can enforce multi-factor authentication (MFA) before granting access. This meets the requirement for application-based policies to use an external authentication source with MFA, as SAML provides a standards-based (SAML 2.0) mechanism for the firewall to trust the IdP's authentication assertions, including MFA status.

Answer

Local user database with password policies

Answer

Kerberos authentication with Active Directory

Answer

RADIUS authentication with one-time passwords via token

Question 3

A network administrator notices that web-browsing traffic is being classified as 'incomplete' in the App-ID table. What is the most likely cause?

Accepted Answer

SSL decryption is not enabled for the traffic.. When SSL decryption is not enabled, the firewall cannot inspect encrypted HTTPS traffic payloads. As a result, App-ID may classify the traffic as 'incomplete' because it cannot match the encrypted payload to the web-browsing application signature. Enabling SSL decryption allows the firewall to decrypt the traffic, inspect the payload, and correctly identify the application.

Answer

The App-ID signature database is outdated.

Answer

The security policy does not have an allow rule for web-browsing.

Answer

The firewall is experiencing asymmetric routing.

Question 4

A network administrator is troubleshooting an issue where HTTPS traffic to a particular website is being blocked. The security policy rule allows SSL traffic to that website. The firewall logs show the traffic is being blocked by the URL Filtering profile. The URL Filtering profile is set to allow the category 'Business-and-Economy'. The website belongs to the category 'Shopping'. What action should the administrator take?

Accepted Answer

Create a custom URL category for the website and set it to allow.. Creating a custom URL category for the specific website and setting it to allow is the best practice to override the category-based blocking without loosening security. Option A is incorrect because changing the profile might affect other traffic. Option B is incorrect because disabling URL Filtering entirely is too broad and could allow malicious traffic. Option D is incorrect because IP-based exclude lists are not recommended as websites can change IPs, and URL filtering decisions are based on URLs, not IPs.

Answer

Change the security policy rule to use a different URL Filtering profile.

Answer

Disable URL Filtering for that traffic flow.

Answer

Add the website's IP address to the URL Filtering exclude list.

Question 5

Which TWO actions can help App-ID correctly identify a custom application that communicates over TCP port 8443 using SSL/TLS with a known internal hostname?

Accepted Answer

Create a custom application with a hostname condition.. A custom application can be defined with a hostname condition to match traffic based on the SNI field in the TLS handshake, which allows App-ID to identify the application even when it uses a non-standard port like 8443. Option E is correct because enabling SSL forward proxy with the internal CA certificate allows the firewall to decrypt the SSL/TLS traffic and inspect the application payload, which is necessary for App-ID to accurately identify the custom application.

Answer

Disable App-ID on port 8443.

Answer

Use an application override with port 8443.

Answer

Add a custom URL category for the domain.

Question 6

Users are unable to authenticate via Captive Portal. The firewall receives authentication requests but they time out. What should be checked first?

Accepted Answer

The authentication sequence settings in the Captive Portal configuration. When the firewall receives authentication requests but they time out, the most common cause is a misconfigured authentication sequence. The authentication sequence defines the order of authentication methods (e.g., local database, RADIUS, LDAP) and their timeout settings. If the sequence is incorrect or the servers are unreachable, the firewall will wait for a response until the timeout expires, causing the Captive Portal authentication to fail. Checking this first isolates the issue efficiently before investigating other components.

Answer

The certificate used for the Captive Portal page

Answer

The session timeout for authenticated users

Answer

The User-ID agent mapping

Question 7

A company uses GlobalProtect for remote access. After upgrading the GP portal and gateway from 5.0 to 5.1, some users cannot connect. They report that they receive 'Unable to connect to gateway' error. The firewall logs show that the user is unable to authenticate. The authentication profile uses LDAP. The administrator can successfully bind to the LDAP server from the firewall CLI. What could be the issue?

Accepted Answer

The authentication sequence changed after upgrade.. After upgrading the GlobalProtect portal and gateway from version 5.0 to 5.1, the authentication sequence may have been reset or changed. If the authentication profile uses LDAP but the sequence now includes a RADIUS server that is unreachable or misconfigured, the user will fail to authenticate even though the LDAP bind works from the CLI. The error 'Unable to connect to gateway' combined with authentication failure points to a change in the authentication order, not a certificate or connectivity issue.

Answer

The LDAP server certificate has expired.

Answer

The RADIUS server is not reachable.

Answer

The GP portal certificate is not trusted by the client.

Question 8

An HA pair is configured with Active/Passive mode. The passive firewall fails to become active after the active firewall's management interface goes down. What is the most likely cause?

Accepted Answer

Management interface failure is not a monitored condition by default. In an Active/Passive HA pair, the passive firewall monitors the active firewall's liveness via the HA1 control link. By default, only the HA1 link failure triggers a failover; the management interface is not monitored for HA state transitions. Therefore, if the management interface goes down but the HA1 link remains up, the passive firewall does not detect a failure and will not become active.

Answer

HA1 keepalive failure is not detected

Answer

HA2 link monitoring is not enabled

Answer

Session synchronization is not complete

Question 9

An administrator configured the authentication profile shown. Users in the domain 'EXAMPLE' are unable to authenticate; logs show 'Authentication failed: user not found'. What is the likely issue?

Accepted Answer

The 'allow-list' is restricting authentication to only user1 and user2. The authentication profile includes an 'allow-list' that explicitly restricts authentication to only 'user1' and 'user2'. When a user from the 'EXAMPLE' domain attempts to authenticate, the firewall checks the allow-list first; since the user is not in that list, the authentication fails with the 'user not found' error, even if the user exists in the domain.

Answer

The Kerberos server profile 'KDC-Profile' is misconfigured

Answer

The expiration time of 60 minutes is too short

Answer

The realm 'EXAMPLE.COM' does not match the domain 'EXAMPLE'

Question 10

When configuring a custom application signature, which field is mandatory to define the application?

Accepted Answer

Protocol. In Palo Alto Networks App-ID, when creating a custom application signature, the Protocol field is mandatory because App-ID uses protocol detection as the first step to identify traffic. Without specifying the protocol (e.g., TCP, UDP, or a specific protocol number), the firewall cannot associate the signature with the correct traffic stream, making the application definition incomplete.

Answer

Category

Answer

Port

Answer

Subcategory

Question 11

After configuring SAML authentication for GlobalProtect, users report they are repeatedly prompted for credentials even though they already authenticated via the IdP. The firewall logs show 'saml-auth-success' but the portal log shows 'user-login-failure: invalid saml assertion'. What is the most likely cause?

Accepted Answer

The firewall and IdP system clocks are out of sync. The firewall logs show 'saml-auth-success' (meaning the IdP successfully authenticated the user and issued a SAML assertion), but the portal log shows 'user-login-failure: invalid saml assertion'. This indicates the firewall received the assertion but rejected it as invalid. The most common cause for a validly signed assertion to be rejected is clock skew between the firewall and the IdP, because SAML assertions contain timestamps (NotBefore and NotOnOrAfter conditions) that are checked against the local system clock. If the clocks differ by more than the allowed skew (typically 5 minutes), the assertion is considered invalid even though it was correctly signed.

Answer

The IdP does not support IdP-initiated SAML flow

Answer

The user mapping agent is not configured

Answer

The SAML identity provider certificate is expired

Question 12

An organization has a pair of PA-5250 firewalls in active/passive HA. During a maintenance window, the active firewall is rebooted. After the reboot, the firewall that was passive becomes active and passes traffic. However, the other firewall remains in a non-functional state and shows 'unknown' as HA state. The administrator checks the HA configuration and finds both firewalls have the same HA settings. What is the most likely issue?

Accepted Answer

The HA control link is down or misconfigured.. After a reboot, the previously active firewall fails to join the HA pair and shows 'unknown' state, which indicates it cannot communicate with its peer. Since both firewalls have identical HA settings, the most likely cause is that the HA control link (the dedicated link used for heartbeat and state synchronization) is down or misconfigured, preventing the rebooted firewall from establishing a valid HA session.

Answer

The backup firewall has a different software version.

Answer

The floating IP addresses are not configured.

Answer

The HA keepalive timer is too short.

Question 13

A network administrator wants to verify if a specific internal IP address (10.1.1.100) is being translated to a public IP when accessing the internet. Which CLI command should be used?

Accepted Answer

show session all filter source 10.1.1.100. The 'show session all filter source 10.1.1.100' command displays active sessions in the firewall's session table, including the source IP, destination IP, and the translated (NAT) IP addresses. This allows the administrator to verify whether the internal IP 10.1.1.100 is being NATed to a public IP when accessing the internet, as the session table shows both the pre-NAT and post-NAT source addresses.

Answer

show running nat-policy

Answer

show nat rule

Answer

show address 10.1.1.100

Question 14

An engineer notices that after an HA failover, the new active firewall is not passing traffic. The show running ip route command shows the default route is missing. What is the most likely cause?

Accepted Answer

Floating static routes were not configured on the passive firewall.. In an active/passive HA pair, static routes are not automatically synchronized from the active to the passive firewall. The passive firewall must have its own static routes configured, often as floating static routes with a higher administrative distance to avoid conflicts during normal operation. When a failover occurs, the new active firewall (formerly passive) lacks the default route because it was never configured or synchronized, causing traffic to fail.

Answer

Static routes were not synchronized.

Answer

OSPF routes were not synchronized.

Answer

BGP routes were not synchronized.

Question 15

A company uses Panorama to manage multiple firewalls. They want to push a security policy that applies to all firewalls but with a specific exception for one firewall in a different region. Which Panorama method should be used?

Accepted Answer

Use a shared policy and override the rule on the specific device group.. Panorama allows a shared policy to be pushed to all firewalls, and you can override a specific rule for a particular device group. By placing the exception rule in the device group that contains the firewall in the different region, you can override the shared policy for that firewall while the rest continue to use the shared policy. This maintains centralized management while accommodating regional exceptions.

Answer

Use a post-rule in the device group.

Answer

Use a device-specific pre-rule.

Answer

Use a template variable.

Question 16

Refer to the exhibit. A site-to-site VPN is configured between two branches. The tunnel is up but traffic is not passing. What is the most likely issue?

Accepted Answer

No security policy allows traffic from the VPN zone.. When a site-to-site VPN tunnel is up but traffic is not passing, the most common cause is the absence of a security policy that permits traffic from the VPN zone to the destination zone. Even if IKE and IPsec SAs are established, the firewall drops the decrypted traffic if no rule explicitly allows it. This is a fundamental Palo Alto Networks concept: tunnel establishment and data forwarding are separate control and data plane functions.

Answer

The IKE gateway is not configured with the correct peer IP.

Answer

The proxy IDs do not match the remote peer.

Answer

The tunnel interface is not assigned to a zone.

Question 17

Order the steps to configure a static route on a Palo Alto Networks firewall.

Accepted Answer

Navigate to the virtual router, add a static route, configure destination and next-hop, then commit.. The correct order to configure a static route on a Palo Alto Networks firewall is: navigate to the appropriate virtual router, add a new static route entry, configure the destination address and next-hop, and then commit the configuration. This ensures the route is properly defined and applied.

Answer

Navigate to the virtual router, configure destination and next-hop, add the static route, then commit.

Answer

Navigate to the virtual router, add a static route, commit, then configure destination and next-hop.

Answer

Add a static route, navigate to the virtual router, configure destination and next-hop, then commit.

Question 18

Arrange the steps to configure a new zone on a Palo Alto Networks firewall in the correct order.

Accepted Answer

Navigate to Network > Zones, then click Add, then enter the zone name and select the zone type, then click OK.. The correct sequence to configure a new zone on a Palo Alto Networks firewall is: first, navigate to Network > Zones; second, click Add to create a new zone object; third, enter the zone name and select the zone type (e.g., Layer3); finally, click OK to save the configuration. This order ensures that the zone is properly created and configured before committing changes.

Answer

Click Add, then navigate to Network > Zones, then enter the zone name and select the zone type, then click OK.

Answer

Navigate to Network > Zones, then enter the zone name and select the zone type, then click Add, then click OK.

Answer

Navigate to Network > Zones, then click Add, then click OK, then enter the zone name and select the zone type.

Question 19

A large enterprise has deployed two Palo Alto Networks PA-5250 firewalls in active/passive HA mode with Panorama for centralized management. The network contains over 10,000 users across multiple sites. Recently, the security team deployed a new security policy rule to block a set of high-risk applications. After the commit, the firewall's CPU utilization spiked to 95% and sessions started to drop intermittently. The firewall logs show a high number of session setup failures and timeouts. The existing security policy contains over 5,000 rules. The new rule uses application-based filtering and is placed near the top of the rulebase. What is the most effective course of action to reduce CPU load while maintaining security?

Accepted Answer

Remove the new rule and implement the blocking via a Threat Prevention profile instead.. The CPU spike is caused by the firewall having to perform application identification (App-ID) on every packet matching the new rule, which is placed near the top of a 5,000-rule policy. By moving the blocking logic to a Threat Prevention profile, the firewall can block the applications at the security profile stage after a faster initial match, reducing the per-session processing overhead. This approach offloads the heavy App-ID processing from the rulebase to a profile that is applied only to relevant traffic, thus lowering CPU utilization while still blocking the high-risk applications.

Answer

Move the new rule to the bottom of the rulebase to reduce matching frequency.

Answer

Convert the new rule to use a simplified service-based filter instead of application-based to reduce processing overhead.

Answer

Increase the session table size and adjust the TCP timewait timeout to reduce session setup overhead.

Question 20

A firewall receives traffic with IP options enabled. How does the firewall handle this traffic by default?

Accepted Answer

It drops the traffic. By default, Palo Alto Networks firewalls drop traffic with IP options enabled because IP options can be used to bypass security controls or evade inspection. The firewall treats such packets as a potential security risk and discards them to prevent IP option-based attacks, such as source routing or timestamp manipulation.

Answer

It forwards the traffic normally

Answer

It logs and alerts

Answer

It strips the IP options and forwards