To ensure high availability (HA) across multiple availability zones (AZs) in a cloud service provider (CSP) environment, using a load balancer with health probes is a recommended method. This setup ensures that traffic can be directed to the healthy NGFW instances across multiple availability zones. If one NGFW instance or availability zone goes down, the load balancer can redirect traffic to the available instance(s) in other zones, providing redundancy and maintaining service availability.

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.

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.

Local firewall rules are evaluated after Panorama pre-rules (those applied before the firewall’s local policies) and before Panorama post-rules (those applied after the firewall’s local policies). This ensures that the local firewall rules do not override the central Panorama policy and are only applied in the appropriate order within the policy evaluation sequence.

In a High Availability (HA) active/passive pair configuration, when setting up an Aggregate Ethernet (AE) interface, enabling the "Enable in HA Passive State" option allows the interface to participate in LACP (Link Aggregation Control Protocol) even when the system is in the passive state. This ensures that the pre-negotiation of the LACP link occurs, allowing the link aggregation to be ready as soon as the firewall becomes active.

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.

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.