// A COMPREHENSIVE GUIDE TO TEACH ME PALO ALTO NEXT-GENERATION FIREWALLS FROM ABSOLUTE ZERO TO ADVANCED MASTERY, COVERING FUNDAMENTALS, ARCHITECTURE, POLICIES, NAT, VPNS, APP-ID, USER-ID, CONTENT-ID, SSL DECRYPTION, LOGGING, PERFORMANCE TUNING, HIGH AVAILABILITY, AND REAL-WORLD TAC-LEVEL TROUBLESHOOTING, ALIGNED WITH ENTERPRISE BEST PRACTICES AND LATEST PAN-OS KNOWLEDGE AS OF DECEMBER 2025. CHAPTERS