IKE and IPSec negotiation events — including successful and failed Phase 1 (IKE SA) and Phase 2 (IPSec SA) exchanges, proposal mismatches, and negotiation timeouts — are recorded by PAN-OS as System log entries, not as part of the Traffic, Tunnel, or Decrypt log facilities, which each capture a different category of information. Because Phase 1 has already completed successfully in this scenario but Phase 2 negotiation appears to be failing or stalling, the actual diagnostic detail explaining why — such as a proxy-ID/traffic-selector mismatch, an unsupported Phase 2 encryption or authentication algorithm, or a PFS group mismatch between the CPE and Prisma Access — will be recorded as a specific IKE/IPSec negotiation message in System logs, making option B the correct log facility to review. Decrypt logs (option A) capture SSL/TLS decryption events for inspected web traffic and have no relevance to IPSec tunnel negotiation, which is a separate control-plane process entirely. Traffic logs (option C) record session-level information for traffic that has already been successfully permitted through a completed policy match; since the tunnel ' s data plane is not yet fully established, there is no session traffic to log in the first place. Tunnel logs (option D) generally reflect the operational status and utilization of an already-established tunnel, not the underlying IKE/IPSec negotiation failure detail needed to diagnose why Phase 2 never completed.