Paloalto Networks PCNSE Palo Alto Networks Certified Security Engineer (PCNSE) PAN-OS 10.2 Exam Practice Test

• A, C, and D are the correct answers because they are the parts of a template that an engineer can configure in Panorama. A template is a collection of device and network settings that can be pushed to multiple firewalls from Panorama1. A template can contain settings such as2:

traffic log would list an application as “not-applicable” if the firewall denied the traffic before the application match could be performed. This can happen if the traffic matches a security rule that is set to deny based on any parameter other than the application, such as source, destination, port, service, etc1. In this case, the firewall does not inspect the application data and discards the traffic, resulting in a “not-applicable” entry in the application field of the traffic log1.

The type of policy in Palo Alto Networks firewalls that can use Device-ID as a match condition is QoS. This is because Device-ID is a feature that allows the firewall to identify and classify devices on the network based on their characteristics, such as vendor, model, OS, and role1. QoS policies are used to allocate bandwidth and prioritize traffic based on various criteria, such as application, user, source, destination, and device2. By using Device-ID as a match condition in QoS policies, the firewall can apply different QoS actions to different types of devices, such as IoT devices, laptops, smartphones, etc3. This can help optimize the network performance and ensure the quality of service for critical applications and devices.

When sizing a decryption firewall deployment, two factors that should be considered are the encryption algorithm and the TLS protocol version. These factors affect the amount of resources and processing power that the firewall needs to decrypt and inspect SSL/TLS traffic.

The encryption algorithm is the method that the server and the client use to encrypt and decrypt the data exchanged in an SSL/TLS session. Different encryption algorithms have different levels of security and performance. For example, AES is a symmetric encryption algorithm that is faster and more efficient than RSA, which is an asymmetric encryption algorithm. However, RSA is more secure than AES because it uses public and private keys to encrypt and decrypt data, while AES uses a single shared key. The firewall must support the encryption algorithms that are used by the servers and clients that it decrypts, and it must have enough CPU and memory resources to handle the decryption workload12.

The TLS protocol version is the standard that defines how the server and the client establish and maintain an SSL/TLS session. Different TLS protocol versions have different features and requirements for encryption algorithms, cipher suites, certificates, handshake messages, etc. For example, TLS 1.3 is the latest and most secure version of TLS, which supports only strong encryption algorithms and cipher suites, such as AES-GCM and ChaCha20-Poly1305, and requires elliptic curve certificates. The firewall must support the TLS protocol versions that are used by the servers and clients that it decrypts, and it must have enough hardware acceleration resources to handle the decryption speed34.

The number of security zones in decryption policies and the number of blocked sessions are not relevant factors for sizing a decryption firewall deployment. The number of security zones in decryption policies only affects how the firewall matches traffic to decryption rules based on source and destination zones, but it does not affect the decryption performance or resource consumption. The number of blocked sessions only indicates how many sessions are denied by the firewall based on security policy or decryption policy rules, but it does not affect the decryption capacity or throughput56.

References: Encryption Algorithms, TLS Protocol Versions, Decryption Policy, PCNSE Study Guide (page 60)

To address the issue of application performance degradation due to excessive VoIP traffic, the administrator should configure QoS on the egress interface for the traffic flows and a QoS profile defining traffic classes. QoS stands for Quality of Service, which is a feature that allows the firewall to manage bandwidth usage and prioritize traffic based on various criteria, such as application, user, service, etc. QoS can help improve the performance and quality of latency-sensitive applications, such as VoIP, by guaranteeing them sufficient bandwidth and priority over other traffic1.

To enable QoS on the firewall, the administrator needs to create a QoS profile and a QoS policy. A QoS profile defines the eight classes of service that traffic can receive, including priority, guaranteed bandwidth, maximum bandwidth, and weight. A QoS policy identifies the traffic that matches a specific class of service based on source and destination zones, addresses, users, applications, services, etc2. The administrator can also create a custom QoS profile or use the default one.

The administrator should apply QoS on the egress interface for the traffic flows, which is the interface where the traffic leaves the firewall. This is because QoS can only shape outbound traffic and not inbound traffic. The egress interface can be either internal or external, depending on the direction of the VoIP traffic. For example, if the VoIP traffic is from internal users to external servers, then the egress interface is the untrust interface facing the ISP. If the VoIP traffic is from external users to internal servers, then the egress interface is the trust interface facing the LAN3.

The administrator should assign a high priority and a sufficient guaranteed bandwidth to the VoIP traffic in the QoS profile. This will ensure that the VoIP packets are processed first by the firewall and are not dropped or delayed due to congestion. The administrator can also limit or block other applications that consume too much bandwidth or pose security risks in the same or different QoS classes4.

An Application Override policy for SIP traffic is not necessary to address this issue. An Application Override policy is used to change or customize the App-ID of certain traffic based on port and protocol criteria. This can be useful for optimizing performance or security for some applications that are difficult to identify or have non-standard behaviors. However, SIP is a predefined App-ID that identifies Session Initiation Protocol (SIP) traffic, which is commonly used for VoIP signaling. The firewall can recognize SIP traffic without an Application Override policy5.

QoS on the ingress interface for the traffic flows is not effective to address this issue. As mentioned earlier, QoS can only shape outbound traffic and not inbound traffic. Applying QoS on the ingress interface will not have any impact on how the firewall handles or prioritizes the incoming packets6.

A QoS policy for each application is not required to address this issue. A QoS policy can match multiple applications in a single rule by using application filters or application groups. This can simplify and consolidate the QoS policy configuration and management. The administrator does not need to create a separate QoS policy for each application unless there is a specific need to assign different classes of service or parameters to each application7.

References: QoS Overview, Configure QoS, QoS Use Cases, QoS Best Practices, Application Override, QoS FAQ, Create a QoS Policy Rule

Schedule content updates so that they download-and-install automatically. Then, set a Threshold that determines the amount of time the firewall waits before installing the latest content. In a security-first network, schedule a six to twelve hour threshold.

A template is a set of configuration options that can be applied to one or more firewalls or virtual systems managed by Panorama. A template can include settings from the Device and Network tabs on the firewall web interface, such as login banner, SSL decryption exclusion, and dynamic updates4. These settings can be configured in a template named “Global” and included in all template stacks. A template stack is a group of templates that Panorama pushes to managed firewalls in an ordered hierarchy4. References: Manage Templates and Template Stacks, PCNSE Study Guide (page 50)

To apply tags automatically based on User-ID logs, the engineer must configure a Log Forwarding profile that specifies the criteria for matching the logs and the tags to apply. The Log Forwarding profile can be attached to a security policy rule or a decryption policy rule to enable auto-tagging for the traffic that matches the rule. The tags can then be used for dynamic address groups, policy enforcement, or reporting1. References: Use Auto-Tagging to Automate Security Actions, PCNSE Study Guide (page 49)

The compare option for a specific rule in the New App Viewer under Policy Optimizer allows an administrator to compare the applications configured in the rule with the applications seen from traffic matching the same rule. This helps the administrator to identify any new applications that are not explicitly defined in the rule, but are implicitly allowed by the firewall based on the dependencies of the configured applications. The compare option also shows the usage statistics and risk levels of the applications, and provides suggestions for optimizing the rule by adding, removing, or replacing applications12. References: New App Viewer (Policy Optimizer), PCNSE Study Guide (page 47)

Why use Security Policy Optimizer and what are the benefits?

If some sites cannot be decrypted due to technical reasons, such as unsupported ciphers, and blocking them is not an option, then the engineer should add the sites to the SSL Decryption Exclusion list to exempt them from decryption. The SSL Decryption Exclusion list is a predefined list of sites that are not subject to SSL decryption by the firewall. The list includes sites that use certificate pinning, mutual authentication, or unsupported cipher suites. The engineer can also add custom sites to the list if they have a valid business reason or technical limitation for not decrypting them34. Adding the sites to the SSL Decryption Exclusion list will allow the traffic to pass through without being decrypted or blocked by the firewall. References: SSL Decryption Exclusion, Troubleshoot Unsupported Cipher Suites

In the second image, VW ports mentioned are 1/5 and 1/7. Hence it can not be a part of any other routing. So if any traffic coming as ingress from 1/7, it has to go out via 1/5.

The egress interface for the traffic with ingress interface ethernet1/7, source 192.168.111.3, and destination 10.46.41.113 will be ethernet1/5. This is because the traffic will match the virtual wire with interfaces ethernet1/5 and ethernet1/7, which is configured to allow VLAN-tagged traffic with tags 10 and 201. The traffic will also match the security policy rule that allows traffic from zone Trust to zone Untrust, which are assigned to ethernet1/7 and ethernet1/5 respectively2. Therefore, the traffic will be forwarded to the same interface from which it was received, which is ethernet1/53.

Virtual Desktop Infrastructure (VDI) and Virtual Machine (VM) environments, such as Citrix XenApp and XenDesktop or VMWare Horizon and Vcenter, support access natively through HTML5. You can RDP, VNC, or SSH to these machines through Clientless VPN without requiring additional third-party middleware. In environments that do not include native support for HTML5 or other web application technologies supported by Clientless VPN, you can use third-party vendors, such as Thinfinity, to RDP through Clientless VPN. Reference:

• B is the best choice for an SSL Forward Untrust certificate because a self-signed certificate generated on the firewall is not trusted by any client browsers by default1. This means that if the firewall observes an invalid or untrusted security certificate from the server, it will present the self-signed certificate to the client, which will trigger an untrusted certificate warning2. This way, the security admin can ensure that users are aware of any potential risks when accessing HTTPS sites with untrusted certificates.
• A web server certificate signed by the organization’s PKI (A) or a subordinate Certificate Authority certificate signed by the organization’s PKI © are not good choices for an SSL Forward Untrust certificate because they are trusted by the client browsers that have the organization’s root CA installed1. This means that if the firewall observes an invalid or untrusted security certificate from the server, it will present the web server or subordinate CA certificate to the client, which will not trigger an untrusted certificate warning2. This way, the security admin cannot ensure that users are aware of any potential risks when accessing HTTPS sites with untrusted certificates.
• A web server certificate signed by an external Certificate Authority (D) is not a good choice for an SSL Forward Untrust certificate because it is trusted by most client browsers that have the external CA in their trust store1. This means that if the firewall observes an invalid or untrusted security certificate from the server, it will present the web server certificate to the client, which will not trigger an untrusted certificate warning2. This way, the security admin cannot ensure that users are aware of any potential risks when accessing HTTPS sites with untrusted certificates.

Verified References:

• 1: How to Configure SSL Decryption - Palo Alto Networks Knowledge Base
• 2: How to Implement and Test SSL Decryption - Palo Alto Networks Knowledge Base

When the peer device will act as the initiator and none of the peer addresses are known, the administrator can enable Passive Mode to establish the VPN connection. Passive Mode tells the firewall to wait for the peer device to initiate the VPN connection. The other options are incorrect. Option A, setting up certificate authentication, would require the administrator to know the peer device's certificate. Option C, using the Dynamic IP address type, would require the administrator to know the peer device's dynamic IP address. Option D, configuring the peer address as an FQDN, would require the administrator to know the peer device's fully qualified domain name.

The firewalls exchange hello messages and heartbeats at configurable intervals to verify that the peer firewall is responsive and operational. Hello messages are sent from one peer to the other to verify the state of the firewall. The heartbeat is an ICMP ping to the HA peer. A response from the peer indicates that the firewalls are connected and responsive.

"A "heartbeat-interval" CLI command was added to the election settings for HA, this interval has a 1000ms minimum for all Palo Alto Networks platforms and is an ICMP ping to the other device through the HA control link."

• A and D are the best practice deployment modes for the firewall if the company wants to add threat prevention to the network without redesigning the network routing. This is because these modes allow the firewall to act as a transparent device that does not affect the existing network topology or routing1.
• A: VirtualWire mode allows the firewall to be inserted into any existing network segment without changing the IP addressing or routing of that segment2. The firewall inspects traffic between two interfaces that are configured as a pair, called a virtual wire. The firewall applies security policies to the traffic and forwards it to the same interface from which it was received2.
• D: Layer 2 mode allows the firewall to act as a switch that forwards traffic based on MAC addresses3. The firewall inspects traffic between interfaces that are configured as Layer 2 interfaces and belong to the same VLAN. The firewall applies security policies to the traffic and forwards it to the appropriate interface based on the MAC address table3.

Verified References:

• 1: https://www.garlandtechnology.com/blog/whats-your-palo-alto-ngfw-deployment-plan
• 2: https://docs.paloaltonetworks.com/pan-os/10-1/pan-os-admin/networking/configure-interfaces/virtual-wire.html
• 3: https://docs.paloaltonetworks.com/pan-os/10-1/pan-os-admin/networking/configure-interfaces/layer-2.html

In an active/active high availability (HA) firewall pair, the firewall that is currently processing traffic is in the “Active” state. This state indicates that the firewall is fully functional and can own sessions and set up sessions. An active firewall can be either active-primary or active-secondary, depending on the Device ID and the HA configuration. An active-primary firewall connects to User-ID agents, runs DHCP server and DHCP relay, and matches NAT and PBF rules with the Device ID of the active-primary firewall. An active-secondary firewall connects to User-ID agents, runs DHCP server, and matches NAT and PBF rules with the Device ID of the active-secondary firewall. An active-secondary firewall does not support DHCP relay1. References: HA Firewall States, PCNSE Study Guide (page 53)

and-destination-nat/source-nat

In order to see what is in a template, the device-group needs the template referenced. Even if you add the firewall to both the template and device-group, the device-group will not see what is in the template. The following link has a video that demonstrates that B is the correct answer.

An authentication portal is a feature that can be used to identify guests and BYOD users, instruct them how to download and install the CA certificate, and clearly notify them that their traffic will be decrypted. An authentication portal is a web page that the firewall displays to users who need to authenticate before accessing the network or the internet. The authentication portal can be customized to include a welcome message, a login prompt, a disclaimer, a certificate download link, and a logout button. The authentication portal can also be configured to use different authentication methods, such as local database, RADIUS, LDAP, Kerberos, or SAML1. By using an authentication portal, the firewall can redirect BYOD users to a web page where they can learn about the decryption policy, download and install the CA certificate, and agree to the terms of use before accessing the network or the internet2.

An SSL decryption profile is not a feature that can be used to identify guests and BYOD users, instruct them how to download and install the CA certificate, and clearly notify them that their traffic will be decrypted. An SSL decryption profile is a set of options that define how the firewall handles SSL/TLS traffic that it decrypts. An SSL decryption profile can include settings such as certificate verification, unsupported protocol handling, session caching, session resumption, algorithm selection, etc3. An SSL decryption profile does not provide any user identification or notification functions.

An SSL decryption policy is not a feature that can be used to identify guests and BYOD users, instruct them how to download and install the CA certificate, and clearly notify them that their traffic will be decrypted. An SSL decryption policy is a set of rules that determine which traffic the firewall decrypts based on various criteria, such as source and destination zones, addresses, users, applications, services, etc. An SSL decryption policy can also specify which type of decryption to apply to the traffic, such as SSL Forward Proxy, SSL Inbound Inspection, or SSH Proxy4. An SSL decryption policy does not provide any user identification or notification functions.

Comfort pages are not a feature that can be used to identify guests and BYOD users, instruct them how to download and install the CA certificate, and clearly notify them that their traffic will be decrypted. Comfort pages are web pages that the firewall displays to users when it blocks or fails to decrypt certain traffic due to security policy or technical reasons. Comfort pages can include information such as the reason for blocking or failing to decrypt the traffic, the URL of the original site, the firewall serial number, etc5. Comfort pages do not provide any user identification or notification functions before decrypting the traffic.

References: Configure an Authentication Portal, Redirect Users Through an Authentication Portal, SSL Decryption Profile, Decryption Policy, Comfort Pages

How to Implement SSH Decryption on a Palo Alto Networks Device

Regardless of whether you generate Forward Trust certificates from your Enterprise Root CA or use a self-signed certificate generated on the firewall, generate a separate subordinate Forward Trust CA certificate for each firewall. The flexibility of using separate subordinate CAs enables you to revoke one certificate when you decommission a device (or device pair) without affecting the rest of the deployment and reduces the impact in any situation in which you need to revoke a certificate. Separate Forward Trust CAs on each firewall also helps troubleshoot issues because the CA error message the user sees includes information about the firewall the traffic is traversing. If you use the same Forward Trust CA on every firewall, you lose the granularity of that information.