NGFW-Engineer Palo Alto Networks Next-Generation Firewall Engineer Questions and Answers

This approach best addresses the enterprise’s requirements for certificate-based authentication, OCSP checks, and consistent policy enforcement:

Distributing the root and intermediate CA certificates via Panorama ensures that all firewalls in the enterprise are consistent in their trust chain and can validate certificates properly.

Configuring OCSP responder profiles on each firewall offloads the revocation checks to an internal OCSP server, which reduces the overhead on the firewalls and ensures fast, real-time certificate status checks.

Using CRL checks as a fallback ensures reliability in case the OCSP responder is unavailable.

Separate certificate profiles for users and devices ensure that the firewall can enforce different security policies based on the type of certificate (user vs. device).

Automated certificate enrollment methods such as Group Policy or SCEP streamline certificate distribution to endpoints, ensuring efficient management of certificates across geographically dispersed firewalls.

Palo Alto Networks Next-Generation Firewalls (NGFWs) use SSL/TLS profiles to secure connections for services such as GlobalProtect Gateways and GlobalProtect Portals. These profiles are used to manage the SSL/TLS encryption and decryption for secure communication between the firewall and clients (such as VPN clients for GlobalProtect). This helps ensure the confidentiality and integrity of the data during transmission.

To enable both RADIUS and SAML authentication to run in parallel during the transition period, you need to configure an authentication sequence and an authentication profile that includes both authentication methods.

By creating an authentication sequence that includes both RADIUS and SAML server profiles, the firewall will attempt authentication with RADIUS first and, if that fails, will fall back to SAML. This enables both authentication types to function simultaneously during the transition period.

You can also configure an authentication profile that includes both the RADIUS Server Profile and the SAML Identity Provider server profile. This setup allows the firewall to use both RADIUS and SAML for authentication requests, and it will check both authentication methods in parallel.

To enable the Advanced Routing Engine (ARE) on a Palo Alto Networks firewall, the license for the ARE must be applied first. Without the proper license, the firewall cannot activate and use the advanced routing features provided by ARE, such as support for more complex routing protocols (e.g., BGP, OSPF, etc.).

Once the license is applied and validated, the routing engine can be configured, allowing the creation of logical routers and routing policies.

Terraform is an Infrastructure-as-Code (IaC) tool that automates the provisioning and management of infrastructure resources, including Palo Alto Networks Next-Generation Firewalls (NGFWs). By using Terraform configuration files, administrators can define and deploy NGFW instances across cloud environments (such as AWS, Azure, and GCP) efficiently and consistently.

Terraform enables:

Automated firewall deployment in cloud environments.

Configuration of security policies and networking settings in a declarative manner.

Scalability and repeatability, reducing manual intervention in firewall provisioning.

To meet the requirement of data isolation for different regional business units while minimizing administrative overhead, the best approach is to establish separate Cloud Identity Engine (CIE) tenants for each business unit. Each tenant would be integrated with the relevant identity sources (such as on-premises AD, Azure AD, and Okta) for that specific region. This ensures that the identity data for each region is kept isolated and only relevant user and group data is distributed to the respective regional firewalls.

By maintaining a strict one-to-one mapping between CIE tenants and business units, the organization ensures that each region’s firewall only receives the user and group data relevant to that region, thus meeting data sovereignty requirements and minimizing administrative complexity.

When implementing a new self-signed root certificate authority (CA) for SSL decryption on a Palo Alto Networks firewall, the subordinate CA certificate (which is generated by the firewall) must be imported into the trust stores of all client devices. This ensures that client devices trust the firewall as a valid certificate authority, enabling the firewall to decrypt and re-encrypt SSL traffic.

Importing the subordinate CA certificate into the client devices' trust stores is necessary for those devices to trust the new self-signed root CA and properly handle SSL decryption traffic.

To successfully implement an IPSec VPN on a Palo Alto Networks NGFW, the security architect must account for two distinct types of traffic:Control Plane(tunnel negotiation) andData Plane(traffic through the tunnel).

First, for the tunnel to establish, the firewall must permit negotiation traffic. While IKE (UDP 500/4500) is the protocol used, Palo Alto Networks uses theIPSec container applicationto represent the underlying encrypted tunnel traffic. This traffic is typically destined for the firewall's own "Local" zone (the management/loopback or physical interface IP). Therefore, a policy must exist to allow theipsec-esp-udpor the broaderIPSecapplication between the external-facing zone and theLocal zone.

Second, once the tunnel is active, the decrypted traffic emerges from theTunnel Interface. This interface must be assigned to a security zone (often a dedicated "VPN" zone or an existing internal zone). Because the NGFW is a stateful, zone-based firewall, theinterzone-defaultpolicy is "Deny" by default. Consequently, a pair of security policies is required to allow data to flow: one for traffic entering the tunnel (e.g., Trust to VPN) and one for traffic exiting the tunnel (e.g., VPN to Trust). Without these specific rules, the tunnel may show as "Up" (Phase 1 and 2 complete), but no production data will pass through it.

In a Multi-VSYS (Virtual System) architecture, Palo Alto Networks firewalls require a specific logical construct to facilitate communication that stays within the physical device. While traditional Layer 3 zones must be bound to physical interfaces, sub-interfaces, or aggregate groups,inter-VSYS communicationrelies on a specialized zone configuration known as theExternalzone type.

When traffic is routed between virtual routers using the next-vr command, the firewall needs a logical "hand-off" point to pass the session from one VSYS context to another. To achieve this, an engineer must create a zone in each VSYS and explicitly set itsType to External. These External zones do not attach to physical ports; instead, they serve as the entry and exit points for the internal backplane.

If the engineer attempts to use a standard Layer 3 zone for this purpose without an associated physical interface, the traffic will fail to egress the source VSYS or ingress the destination VSYS. Even if theSecurity PolicyandVirtual Routersettings are technically accurate, the session cannot be established because the logical path is incomplete. Therefore, assigning theExternal zone typeis a mandatory architectural requirement to bridge the gap between two logically separated virtual systems within the same hardware chassis.

In Palo Alto Networks firewalls, each virtual system (VSYS) is typically isolated from other VSYSs, meaning that traffic between different VSYSs cannot pass through the firewall by default. In this case, since the interfaces for each VSYS are assigned to separate virtual routers (VRs), and the desired traffic is still not passing between the two VSYSs, the firewall needs to be explicitly configured to allow traffic between them.

The required configuration is to add each VSYS to the list of visible virtual systems of the other VSYS. This allows inter-VSYS communication to be enabled, effectively permitting the traffic to pass between the zones of different VSYSs.

When integrating Kubernetes with Palo Alto Networks NGFWs, the CN-Series firewalls are specifically designed to secure traffic between microservices in containerized environments. These firewalls provide advanced security features like Application Identification (App-ID), URL filtering, and Threat Prevention to secure communication between containers and microservices within a Kubernetes environment.

To ensure continuous, secure connectivity and consistent policy enforcement with GlobalProtect in an enterprise environment that uses user- and machine-based certificate authentication, the approach should:

Distribute root and intermediate CAs via Panorama templates: This ensures that all firewalls managed by Panorama share the same trusted certificate authorities for consistency and security.

Use distinct certificate profiles for user vs. machine certificates: This enables separate handling of user and machine authentication, ensuring that both types of certificates are managed and validated appropriately.

Reference an internal OCSP responder: By integrating OCSP checks, the firewall can validate certificate revocation in real-time, meeting the security requirement while minimizing the overhead and latency associated with traditional CRLs (Certificate Revocation Lists).

Automate certificate deployment with Group Policy: This ensures that machine certificates are deployed in a consistent and scalable manner across the enterprise, reducing manual intervention and minimizing user disruption.

This approach supports the requirements for pre-logon, OCSP checks, and minimal user disruption, while maintaining a secure, automated, and consistent authentication process across all firewalls managed via Panorama.

In the context of virtual systems (VSYS) on a Palo Alto Networks firewall, the external zone is typically associated with specific interfaces within a VSYS. Zones are fundamental security objects used to define traffic flow between interfaces, and the external zone would be used for interfaces that connect to external networks.

An external zone is associated with an interface within a VSYS of the firewall. This ensures that traffic from specific interfaces can be classified as belonging to the external zone, allowing the firewall to apply appropriate security policies.

The external zone is indeed a security object that is specific to a given VSYS, as each VSYS can have its own set of zones that are isolated from others.

In the context of GlobalProtect with certificate-based authentication, certificate profiles are used to ensure proper validation of the certificates. They perform the following functions:

Define trust anchors, which are the root and intermediate Certificate Authorities (CAs) that the firewall trusts to authenticate certificates.

Specify revocation checks, such as CRL (Certificate Revocation List) and OCSP (Online Certificate Status Protocol), to ensure that the certificates being used have not been revoked.

Map certificate attributes, such as the Common Name (CN), which helps in authenticating users and devices based on their certificates.

This approach meets all the requirements for securing east-west traffic within each Kubernetes cluster, maintaining consistent security policies across on-premises and cloud environments, and allowing for dynamic scaling of the CN-Series NGFWs as containerized workloads spin up or down. By using Kubernetes-native deployment tools (such as Helm), the CN-Series NGFWs can be deployed and scaled dynamically within each cluster. Local insertion into the service mesh or CNI ensures that the NGFW can inspect traffic at the appropriate points within the cluster.

Centralized management via Panorama ensures that security policies are uniform across both on-premises and cloud environments, providing visibility and control across all clusters.