https://docs.paloaltonetworks.com/vm-series/8-1/vm-series-deployment/set-up-the-vm-series- firewall-on-aws/high-availability-for-vm-series-firewall-on-aws/configure-activepassive-ha-on- aws.html

In a Palo Alto Networks firewall, when configuring User-ID, there are two essential components that must be configured: User Mapping and Group Mapping.
* User Mapping involves identifying users by their usernames, which helps in associating network traffic with user activity. This is critical for applying user-specific policies and monitoring user activities.
* Group Mapping involves associating users with their respective groups, typically pulled from a directory
* service like LDAP. This allows the firewall to apply policies based on group membership, making it easier to manage policies for large numbers of users.
These components enable the firewall to enforce security policies based on user identity and group membership, enhancing overall network security by ensuring that policies are applied accurately.

When beginning to understand the Zero Trust protect surface using the Palo Alto Networks Zero Trust reference architecture, the following two steps are crucial:
* Validate User Identities through Authentication (A): This step involves ensuring that all users are authenticated properly. By verifying the identities of users attempting to access the network, organizations can ensure that only authorized users can access sensitive resources. This is a fundamental principle of Zero Trust, which operates on the premise of "never trust, always verify."
* Categorize Data and Applications by Levels of Sensitivity (C): This involves identifying and classifying data and applications based on their sensitivity and importance to the organization. By understanding what needs to be protected and the level of sensitivity, security policies can be tailored to provide appropriate levels of protection. This helps in prioritizing security measures based on the criticality of the data and applications.
References:
* Palo Alto Networks, Zero Trust Architecture Documentation.
* NIST Zero Trust Architecture (NIST SP 800-207).