PCSFE Palo Alto Networks Certified Software Firewall Engineer (PCSFE) Questions and Answers

Using the management interface as the HA1 backup link helps avoid split brain in active-passive high availability (HA) pair deployment. High availability (HA) is a feature that provides redundancy and failover protection for firewalls in case of hardware or software failure. Active-passive HA is a mode of HA that consists of two firewalls in a pair, where one firewall is active and handles all traffic, while the other firewall is passive and acts as a backup. Split brain is a condition that occurs when both firewalls in an HA pair assume the active role and start processing traffic independently, resulting in traffic duplication, policy inconsistency, or session disruption. Split brain can be caused by network failures, device failures, or configuration errors that prevent the firewalls from communicating their HA status and synchronizing their configurations and sessions. Using the management interface as the HA1 backup link helps avoid split brain in active-passive HA pair deployment. The HA1 interface is used for exchanging HA state information and configuration synchronization between the firewalls. Using the management interface as the HA1 backup link provides redundancy and failover protection for the HA1 interface, ensuring that the firewalls can maintain their HA communication and avoid split brain. Using a standard traffic interface as the HA2 backup, enabling preemption on both firewalls in the HA pair, or using a standard traffic interface as the HA3 link do not help avoid split brain in active-passive HA pair deployment, but they are related features that can enhance performance and reliability. References: Palo Alto Networks Certified Software Firewall Engineer (PCSFE), [High Availability Overview], [Configure HA Backup Links], [Configure Heartbeat Backup]

TLS decryption is the offering that inspects encrypted outbound traffic. TLS decryption is a feature that allows the firewall to decrypt and inspect outbound SSL/TLS traffic from internal clients to external servers. TLS decryption can inspect encrypted outbound traffic by applying threat prevention technologies, such as antivirus, anti-spyware, vulnerability protection, URL filtering, file blocking, data filtering, and WildFire analysis, to the decrypted traffic and blocking any malicious content or activity. WildFire, Content-ID, and Advanced URL Filtering (AURLF) are not offerings that inspect encrypted outbound traffic, but they are related solutions that can enhance security and visibility. References: Palo Alto Networks Certified Software Firewall Engineer (PCSFE), [TLS Decryption Overview], [Threat Prevention Datasheet]

The appropriate file format for Kubernetes applications is .yaml. YAML is a human-readable data serialization language that is commonly used for configuration files. Kubernetes applications are defined and deployed using YAML files that specify the desired state and configuration of the application components, such as pods, services, deployments, or ingresses. YAML files for Kubernetes applications follow a specific syntax and structure that adhere to the Kubernetes API specifications. .exe, .json, and .xml are not appropriate file formats for Kubernetes applications, but they are related formats that can be used for other purposes. References: Palo Alto Networks Certified Software Firewall Engineer (PCSFE), [What is YAML?], [Kubernetes Basics], [Kubernetes API Overview]

A design consideration for a prospect who wants to deploy VM-Series firewalls in an Amazon Web Services (AWS) environment is that only active-passive high availability (HA) is supported. High availability (HA) is a feature that provides redundancy and failover protection for firewalls in case of hardware or software failure. Active-passive HA is a mode of HA that consists of two firewalls in a pair, where one firewall is active and handles all traffic, while the other firewall is passive and acts as a backup. Active-passive HA is the only mode of HA that is supported for VM-Series firewalls in an AWS environment, due to the limitations of AWS networking and routing. Active-active HA, which is another mode of HA that consists of two firewalls in a pair that both handle traffic and synchronize sessions, is not supported for VM-Series firewalls in an AWS environment. A design consideration for a prospect who wants to deploy VM-Series firewalls in an AWS environment is not that special AWS plugins are needed for load balancing, resources are shared within the cluster, or high availability (HA) clusters are limited to fewer than 8 virtual appliances, as those are not valid or relevant factors for firewall deployment in an AWS environment. References: Palo Alto Networks Certified Software Firewall Engineer (PCSFE), [High Availability Overview], [High Availability on AWS]

App-ID is the component that can provide application-based segmentation and prevent lateral threat movement. Application-based segmentation is a method of dividing the network into smaller segments or zones based on application or workload characteristics, such as function, dependency, owner, or security posture. Lateral threat movement is a technique used by attackers to move across the network from one compromised host to another, looking for sensitive data or assets. App-ID is a feature that identifies and classifies applications and protocols based on their content and characteristics, regardless of port, encryption, or evasion techniques. App-ID can provide application-based segmentation and prevent lateral threat movement by applying granular security policies based on application information to each segment or connection, blocking unauthorized access or data exfiltration. DNS Security, NAT, and URL Filtering are not components that can provide application-based segmentation and prevent lateral threat movement, but they are related features that can enhance security and visibility. References: Palo Alto Networks Certified Software Firewall Engineer (PCSFE), [App-ID Overview], [Microsegmentation with Palo Alto Networks], [Lateral Movement]

Software next-generation firewall (NGFW) credits can be used to provision migrating NGFWs from hardware to VMs. Software NGFW credits are a flexible licensing model that allows customers to purchase and consume software NGFWs as needed, without having to specify the platform or deployment model upfront. Customers can use software NGFW credits to migrate their existing hardware NGFWs to VM-Series firewalls on any supported cloud or virtualization platform, or to deploy new VM-Series firewalls as their needs grow. Software NGFW credits cannot be used to provision remote browser isolation, virtual Panorama appliances, or enablement of DNS security, as those are separate solutions that require different licenses or subscriptions. References: Palo Alto Networks Certified Software Firewall Engineer (PCSFE), [Software NGFW Credits Datasheet], [Software NGFW Credits FAQ]

Auto scaling templates for VM-Series firewalls enable deployment of a single auto scaling group (ASG) of VM-Series firewalls to secure inbound traffic from the internet to Amazon Web Services (AWS) application workloads. An ASG is a collection of EC2 instances that share similar characteristics and can be scaled up or down automatically based on demand or predefined conditions. Auto scaling templates for VM-Series firewalls are preconfigured templates that provide the necessary resources and configuration to deploy and manage VM-Series firewalls in an ASG on AWS. Auto scaling templates for VM-Series firewalls can be used to secure inbound traffic from the internet to AWS application workloads by placing the ASG of VM-Series firewalls behind an AWS Application Load Balancer (ALB) or a Gateway Load Balancer (GWLB) that distributes the traffic across the firewalls. The firewalls can then inspect and enforce security policies on the inbound traffic before sending it to the application workloads. Auto scaling templates for HA-Series, CN-Series, and IPA-Series firewalls do not enable deployment of a single ASG of VM-Series firewalls to secure inbound traffic from the internet to AWS application workloads, as those are different types of firewalls that have different deployment models and use cases. References: Palo Alto Networks Certified Software Firewall Engineer (PCSFE), [Auto Scaling the VM-Series Firewall on AWS], [VM-Series Datasheet], [HA-Series Datasheet], [CN-Series Datasheet], [IPA-Series Datasheet]

Traffic is directed to a Palo Alto Networks firewall integrated with Cisco ACI through a policy-based redirect. Cisco ACI is a software-defined network (SDN) solution that provides network automation, orchestration, and visibility. A policy-based redirect is a mechanism that allows Cisco ACI to redirect traffic from one endpoint group (EPG) to another EPG through a service device, such as a Palo Alto Networks firewall. The firewall can then inspect and enforce security policies on the redirected traffic before sending it back to Cisco ACI. Traffic is not directed to a Palo Alto Networks firewall integrated with Cisco ACI by using contracts between endpoint groups that send traffic to the firewall using a shared policy, through a virtual machine (VM) monitor domain, or by creating an access policy, as those are not valid methods for traffic redirection in Cisco ACI. References: Palo Alto Networks Certified Software Firewall Engineer (PCSFE), [Deploy the VM-Series Firewall on Cisco ACI], [Cisco ACI Policy-Based Redirect]

VM-Series firewalls and hardware firewalls that are external to the Kubernetes cluster are problematic for protecting containerized workloads because they are located outside the cluster and have no visibility into application-level cluster traffic. Kubernetes is a platform that provides orchestration, automation, and management of containerized applications. Kubernetes cluster traffic consists of traffic between containers within a pod, across pods, or across namespaces. VM-Series firewalls and hardware firewalls that are external to the Kubernetes cluster cannot inspect or control this traffic, as they only see the encapsulated or aggregated traffic at the network layer. This creates blind spots and security gaps for containerized workloads. VM-Series firewalls and hardware firewalls that are external to the Kubernetes cluster are not problematic for protecting containerized workloads because they do not scale independently of the Kubernetes cluster, are managed by another entity when located inside the cluster, or function differently based on whether they are located inside or outside of the cluster, as those are not valid reasons or scenarios for firewall deployment in a Kubernetes environment. References: Palo Alto Networks Certified Software Firewall Engineer (PCSFE), [CN-Series Concepts], [VM-Series on Kubernetes]

The two methods of Zero Trust implementation that can benefit an organization are:

• Boundaries are established
• Access controls are enforced

Zero Trust is a security model that assumes no trust for any entity or network segment, and requires continuous verification and validation of all connections and transactions. Zero Trust implementation can benefit an organization by improving its security posture, reducing its attack surface, and enhancing its visibility and compliance. Boundaries are established is a method of Zero Trust implementation that involves defining and segmenting the network into smaller zones based on data sensitivity, user identity, device type, or application function. Boundaries are established can benefit an organization by isolating and protecting critical assets from unauthorized access or lateral movement. Access controls are enforced is a method of Zero Trust implementation that involves applying granular security policies based on the principle of least privilege to each zone or connection. Access controls are enforced can benefit an organization by preventing data exfiltration, malware propagation, or credential theft. Compliance is validated and security automation is seamlessly integrated are not methods of Zero Trust implementation, but they may be potential outcomes or benefits of implementing Zero Trust. References: Palo Alto Networks Certified Software Firewall Engineer (PCSFE), [Zero Trust Security Model], [Zero Trust Network Security]

The partition can be accomplished without editing the IP addresses or the default gateways of any of the guest VMs by creating a new virtual switch and using the VM-Series firewall to separate virtual switches using virtual wire mode. Then move the guests that require more security into the new virtual switch. A virtual switch is a software-based switch that connects virtual machines (VMs) in a VMware ESXi environment. A virtual wire is a deployment mode of the VM-Series firewall that allows it to act as a bump in the wire between two network segments, without requiring an IP address or routing configuration. By creating a new virtual switch and using the VM-Series firewall to separate virtual switches using virtual wire mode, the customer can isolate the group of VMs that require more security from the rest of the network, and apply security policies to the traffic passing through the firewall. The partition cannot be accomplished without editing the IP addresses or the default gateways of any of the guest VMs by editing the IP address of all of the affected VMs, creating a Layer 3 interface in the same subnet as the VMs and then configuring proxy Address Resolution Protocol (ARP), or sending the VLAN out of the virtual environment into a hardware Palo Alto Networks firewall in Layer 3 mode. Use the same IP address as the old default gateway, then delete it, as those methods would require changing the network configuration of the guest VMs or introducing additional complexity and latency. References: Palo Alto Networks Certified Software Firewall Engineer (PCSFE), [Deploying Virtual Switches], [Virtual Wire Deployment], [Deploying Virtual Wire on VMware ESXi]

To deploy a VM-Series firewall on NSX, you need to enable communication between Panorama and the NSX Manager. This allows Panorama to receive information about the virtual machines and services in the NSX environment. You also need to register the VM-Series firewall as a service on the NSX Manager. This allows NSX to redirect traffic to the VM-Series firewall for inspection3. References: VM-Series Deployment Guide for VMware NSX

Geneve is the protocol used for communicating between VM-Series firewalls and a gateway load balancer in Amazon Web Services (AWS). A gateway load balancer is a type of network load balancer that distributes traffic across multiple virtual appliances, such as VM-Series firewalls, in AWS. Geneve is a tunneling protocol that encapsulates the original packet with an additional header that contains metadata about the source and destination endpoints, as well as other information. Geneve allows the gateway load balancer to preserve the original packet attributes and forward it to the appropriate VM-Series firewall for inspection and processing. VRLAN, GRE, and VMLAN are not protocols used for communicating between VM-Series firewalls and a gateway load balancer in AWS, but they are related concepts that can be used for other purposes. References: Palo Alto Networks Certified Software Firewall Engineer (PCSFE), [Deploy the VM-Series Firewall with AWS Gateway Load Balancer], [Geneve Protocol Specification]

DNS Security is a service that provides inbound traffic protection by preventing DNS-based attacks. DNS Security uses machine learning and threat intelligence to identify and block malicious domains, command and control (C2) traffic, and DNS tunneling. References: [DNS Security]

Microsegmentation is a technology that allows for granular control of east-west traffic in a software-defined network. Microsegmentation divides the network into smaller segments or zones based on application or workload characteristics, and applies security policies to each segment. This reduces the attack surface and prevents unauthorized access or lateral movement within the network. Routing, MAC Access Control List, and Virtualization are not technologies that provide microsegmentation, but they are related concepts that can be used in conjunction with microsegmentation. References: Palo Alto Networks Certified Software Firewall Engineer (PCSFE), [Microsegmentation with Palo Alto Networks], [Microsegmentation for Dummies]