Palo Alto PA-220 Reference Policy Layout

Overview

This reference outlines the zone architecture, interface assignments, and security policy structure for a Palo Alto PA-220 firewall serving as the perimeter security device in a small-to-medium reference platform environment.

Context and Assumptions

• PA-220 firewall with appropriate licensing (Threat Prevention, WildFire, etc.)
• Internet connection via ethernet1/1 interface
• Internal network segments require micro-segmentation
• Management access from dedicated administrative network
• Network topology supports VLAN segmentation via Layer 3 interfaces

Architecture

The PA-220 serves as both the internet gateway and internal segmentation point, using zone-based policies to control traffic flow between network segments. Interface roles include untrusted (internet), trusted (general LAN), and specialized zones for infrastructure services.

Implementation Notes

Zone design follows the principle of least privilege with default-deny policies. Critical considerations include proper NAT policy ordering, application-based rules rather than port-based rules, and logging configuration for security monitoring and compliance.

Commands and Configuration

# Example zone and interface configuration via CLI
configure
set network interface ethernet ethernet1/1 layer3 ip 203.0.113.10/30
set zone untrust network layer3 ethernet1/1

set network interface ethernet ethernet1/2 layer3 units ethernet1/2.100 ip 10.0.100.1/24
set zone trusted network layer3 ethernet1/2.100

commit

Operational Notes

• Regularly review security policy hit counts and unused rules
• Monitor threat logs for attack patterns and false positives
• Performance considerations: PA-220 throughput limits with full feature set enabled
• Backup configuration before major changes using device state snapshots

Related Entries

This configuration integrates with VLAN design patterns and complements identity-based network access controls implemented through 802.1X or similar technologies.