Basic Concept: When interoperating with policy-based VPN devices such as Cisco ASA or Check Point, Proxy IDs identify the local and remote selectors that must match Phase 2/IPSec SAs.
Why B is Correct: Matching Proxy IDs resolves the failure because the ASA expects specific encryption domains; without matching selectors, IKE Phase 2 negotiation fails or traffic does not match the correct SA.
Why A is Wrong: Ensure that an active static or dynamic route exists for the VPN peer with next hop as the tunnel interface. relates to VPN configuration, but it does not address the specific PAN-OS requirement for selectors, tunnel interface functions, routing, or Security policy in this scenario.
Why C is Wrong: Check that IPSec is enabled in the management profile on the external interface. relates to VPN configuration, but it does not address the specific PAN-OS requirement for selectors, tunnel interface functions, routing, or Security policy in this scenario.
Why D is Wrong: Validate the tunnel interface VLAN against the peer’s configuration. relates to VPN configuration, but it does not address the specific PAN-OS requirement for selectors, tunnel interface functions, routing, or Security policy in this scenario.
