#L2 Interfaces In a Layer2 deployment (Layer3 VLAN Interfaces (SVI) created in Layer3 Switch) the firewall provides MAC layer switching between two or more logical networks. The network provides L2 connectivity between networks where firewall segmentation is desired without changing the L3 topology. Each group of interfaces must be assigned to a VLAN, and additional Layer 2 subinterfaces can be defined as needed. Choose this option when switching is required. Advantages: Visibility into network traffic o Device can take action on the traffic, such as block or perform QoS Disadvantages: The device does not participate in spanning tree #L3 Interfaces In a Layer 3 deployment (Layer3 VLAN Interfaces (SVI)created in both Palo Alto Layer3 Switch) the firewall routes traffic between multiple interfaces. An IP address must be assigned to each interface and a virtual router must be defined to route the traffic. Choose this option when routing or NAT is required. Advantages: Full firewall functionality, such as traffic visibility, blocking traffic, rate limiting traffic, NAT, and routing, including support for common routing protocols Disadvantages: Inserting device into network will require IP configuration changes on adjacent devices https://live.paloaltonetworks.com/twzvq79624/attachments/twzvq79624/IntegrationArticles/29/1/PaloAltoNetworks-Designs-Guide-RevB.pdf https://live.paloaltonetworks.com/t5/Featured-Articles/Getting-Started-Layer-3-Subinterfaces/ta-p/67395
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