Palo Alto Networks firewalls provide the capability to capture packets at various stages of processing. Understanding these stages is crucial for effective troubleshooting and is a key topic in the PCNSE exam.
Definition: Captures packets as they enter the firewall's ingress interface, before any processing like NAT, policy evaluation, or decryption occurs.
Use Cases:
PCNSE Focus: Understanding that this stage shows the packet in its original form, which is crucial for identifying issues before any firewall processing.
Definition: Captures packets after initial processing, such as policy evaluation, but before NAT or forwarding decisions.
Use Cases:
PCNSE Focus: Recognizing the impact of security policies and how they influence packet handling at this stage.
Definition: Captures packets as they exit the firewall's egress interface, after all processing, including NAT and policy enforcement.
Use Cases:
PCNSE Focus: Understanding how NAT and other processing affect the final packet sent from the firewall.
Definition: Captures packets that the firewall has decided to drop, due to reasons like policy violations, malformed packets, or threats.
Use Cases:
PCNSE Focus: Being able to determine why packets are dropped and how to use this information for troubleshooting.