NSE7-SSE-AR-26: Fortinet NSE 7 - FortiSASE 26 Architect

Prefer Passive uses observed TCP sessions for passive health measurement while traffic is present. Passive measurement does not send probes, so it cannot determine whether a member is alive or dead during that passive-monitoring interval. When no TCP traffic has been seen for three minutes, FortiGate begins active probing; the three-minute interval is not a fallback-to-passive timer. Enabling passive WAN health measurement also disables hardware/ASIC offloading for the applicable firewall policy.