PCNSE Exam Dumps - Paloalto Networks Palo Alto Certifications and Accreditations Questions and Answers

When implementing an application override in a Palo Alto Networks firewall, the primary goal is to explicitly define how specific traffic is identified and processed by the firewall, bypassing the regular App-ID process. This is particularly useful for traffic that might be misidentified by App-ID or for applications that require special handling for performance reasons.

To successfully implement application override, the following items must be configured:

B. Application override policy rule:This is a specialized policy rule that you create to specify the criteria for the traffic you want to override. In this rule, you define the source and destination zones, addresses, and ports. Instead of relying on the App-ID engine to identify the application, the firewall uses the criteria defined in the application override policy to classify the traffic.

C. Security policy rule:After defining an application override policy, you must also configure a security policy rule to allow the overridden traffic through the firewall. This rule specifies the action (allow, deny, drop, etc.) for the traffic that matches the application override policy. It's essential to ensure that the security policy rule matches the traffic defined in the application override policy to ensure that the intended traffic is allowed through the firewall.

For detailed guidance on configuring application override and the necessary security policies, refer to the official Palo Alto Networks documentation. This resource provides step-by-step instructions and best practices for effectively managing traffic using application overrides.

The CLI command "show system state filter-pretty sys.sl.p8.phy" is used to display detailed physical layer information, which would include the physical media connected to a specific interface such as ethernet1/8. This command is designed to filter the output to show relevant physical layer information for the specified interface.For more information on Palo Alto Networks CLI commands and their outputs, refer to the "PAN-OS® CLI Reference Guide".

The two key exchange algorithms that consume the most resources when decrypting SSL traffic are ECDHE and DHE. These are both Diffie-Hellman based algorithms that enable perfect forward secrecy (PFS), which means that they generate a new and unique session key for each SSL/TLS session, and do not reuse any previous keys. This enhances the security of the encrypted communication, but also increases the computational cost and complexity of the key exchange process. ECDHE stands for Elliptic Curve Diffie-Hellman Ephemeral, which uses elliptic curve cryptography (ECC) to generate the session key. DHE stands for Diffie-Hellman Ephemeral, which uses modular arithmetic to generate the session key. Both ECDHE and DHE require more CPU and memory resources than RSA, which is a non-PFS algorithm that uses public and private keys to encrypt and decrypt the session key123. References: Key Exchange Algorithms, Best Practices for Enabling SSL Decryption, PCNSE Study Guide (page 60)

For virtual systems (vSys) on a Palo Alto Networks firewall to communicate with each other, especially when separate virtual routers (VRs) are used for each vSys, the configuration must facilitate proper routing and security policy enforcement. The key aspects to focus on include:

A. External zones with the virtual systems added:

External zones are special types of zones that are used to facilitate traffic flow between virtual systems within the same physical firewall. By adding virtual systems to an external zone, you enable them to communicate with each other, effectively bypassing the need for traffic to exit and re-enter the firewall.

D. Add a route with next hop next-vr by using the VR configured in the virtual system:

When using separate VRs for each vSys, it's essential to configure inter-VR routing. This is done by adding routes in each VR with the next hop set to 'next-vr', specifying the VR of the destination vSys. This setup enables traffic to be routed from one virtual system's VR to another, facilitating communication between them.

E. Ensure the virtual systems are visible to one another:

Visibility between virtual systems is a prerequisite for inter-vSys communication. This involves configuring the virtual systems in a way that they are aware of each other's existence. This is typically managed in the vSys settings, where you can specify which virtual systems can communicate with each other.

By focusing on these configuration details, the network security engineer can ensure that the virtual systems can communicate effectively, maintaining the necessary isolation while allowing the required traffic flow.

 The correct packet-flow sequence is C. PBF > Static route > Security policy enforcement. This sequence describes the order of operations that the firewall performs when processing a packet. PBF stands for Policy-Based Forwarding, which is a feature that allows the firewall to override the routing table and forward traffic based on the source and destination addresses, application, user, or service. PBF is evaluated before the static route lookup, which is the default method of forwarding traffic based on the destination address and the longest prefix match. Security policy enforcement is the stage where the firewall applies the security policy rules to allow or block traffic based on various criteria, such as zone, address, port, user, application, etc12. References: Policy-Based Forwarding, Packet Flow Sequence in PAN-OS

To prevent the import from affecting ongoing traffic when you import the configuration of an HA pair into Panorama, you should disable config sync on both firewalls. Config sync is a feature that enables the firewalls in an HA pair to synchronize their configurations and maintain consistency. However, when you import the configuration of an HA pair into Panorama, you want to avoid any changes to the firewall configuration until you verify and commit the imported configuration on Panorama. Therefore, you should disable config sync before importing the configuration, and re-enable it after committing the changes on Panorama12. References: Migrate a Firewall HA Pair to Panorama Management, PCNSE Study Guide (page 50)

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