Palo Alto Networks Exam PCNSE Topic 4 Question 83 Discussion

External zones are a unique zone type on Palo Alto Networks firewalls that facilitate the movement of traffic between virtual systems on the same physical appliance. These zones are required when multiple virtual systems (vsys) are configured on a single firewall and there is a need to allow inter-vsys traffic without the need for the traffic to leave the firewall and re-enter. An external zone is associated with a specific virtual system and enables traffic to pass from one virtual system to another securely, thereby simplifying traffic management and reducing the need for additional physical interfaces or external routing to handle inter-vsys communication.