Separate rules must be created for each direction: Palo Alto Networks firewalls enforce security policies based on traffic direction. To allow bidirectional communication through the IPSec tunnel, two separate rules are required - one for incoming and one for outgoing traffic.
IKE negotiation and IPSec/ESP packets are denied by default: Palo Alto Networks firewalls use an interzone default deny policy, meaning that unless an explicit policy allows IKE (UDP
500/4500) and ESP (protocol 50) traffic, the firewall will block these packets, preventing tunnel establishment. Therefore, administrators must create explicit rules permitting IKE and IPSec/ESP traffic to the firewall's external interface.

Virtual Wire (transparent) mode allows the NGFW to inspect traffic without modifying the network topology.

Assigning an Admin Role Profile to a user in a Palo Alto Networks NGFW is used to define granular permissions for management tasks. This allows administrators to control what actions a user can perform on the firewall, such as configuration changes, monitoring, and logging. By assigning different admin roles, you can ensure that users have access only to the areas and tasks they need, enforcing the principle of least privilege.

The HA3 interface, a Layer 2 link using MAC-in-MAC encapsulation, enables packet forwarding between active/active firewalls to handle asymmetric routing and ensure proper session setup when traffic arrives at the non-owner peer.

In a hybrid cloud deployment, Ansible is primarily used for automating configurations and policy updates on Palo Alto Networks Next-Generation Firewalls (NGFWs). Through the use of playbooks, Ansible can automate the process of deploying security policies, updating configurations, and managing the firewall's state, which enhances efficiency and consistency across multiple NGFWs in a large or hybrid cloud environment.