Fortinet Updated FCSS_NST_SE-7.6 Exam Questions and Answers by tahlia

The output of the diagnose sys session list command provides the critical evidence needed to determine the behavior during a failover:

Session Synchronization (synced):

The most important indicator in the exhibit is the synced flag located in the state= line (state=may_dirty synced none app_ntf).

In FortiOS HA (High Availability), the synced flag confirms that this specific session has been successfully synchronized from the primary device to the secondary (backup) device.

Session synchronization (Session Pickup) ensures that if the primary unit fails, the secondary unit already has the session in its table and can resume traffic processing immediately.

TCP State (proto_state=01):

The output shows proto=6 (TCP) and proto_state=01.

In the FortiGate session table, proto_state=01 for TCP indicates that the session is in the ESTABLISHED state (post-three-way handshake).

This invalidates Option B, which claims the TCP session is not fully established.

Failover Outcome:

Because the session is ESTABLISHED and SYNCED, the secondary device will seamlessly take over the session upon primary failure.

The traffic continues to flow through the new primary without requiring the user/client to restart the connection. This is the primary function of HA Session Pickup.

Why other options are incorrect:

A: While the output shows app_ntf (Application Control notification) and may_dirty, the presence of the synced flag overrides this concern regarding failover. If the session type were not supported for failover (e.g., certain proxy sessions in older versions), it would not be marked as synced. Since it is synced, it persists.

B: As noted, proto_state=01 means established, not " not fully established " .

D: While the kernel updates routing tables, the purpose of syncing the session is to preserve the state so it does not need to be re-evaluated as a new packet would, preventing traffic drops.

The session output includes the flags:

state=redir local may_dirty ...

npu_state=00000000

offload=0/0

The 7.6 study guide explains these flags directly:

local = “Session is to/from local stack”

redir = “Session is being processed by an application layer proxy”

may_dirty = “Session is allowed by a firewall policy”

This makes C correct, because the local flag means the session either originates from FortiGate or terminates on FortiGate . The FortiOS administration guide states the same meaning: “Session is originated from or destined for local stack.”

This also makes A correct. The redir flag means the session is handled by an application-layer proxy . FortiOS documents explain that proxy-based inspection buffers traffic on the FortiGate and inspects it there, and that proxy-based processing is CPU and memory-intensive

Since the session also shows no NPU offload (npu_state=00000000, offload=0/0), this traffic is being handled in software/CPU, not by the NPU.

Why the other options are wrong:

B is wrong because the redir flag proves the session is not passing without inspection; it is being processed by an application-layer proxy

D is wrong because there is no authentication flag in this session. In Fortinet examples of captive portal/authentication-related sessions, the session state includes auth or authed flags. The study guide shows: “Any session for traffic coming from an authenticated user contains the authed flag.” This exhibit does not show auth or authed, so there is no basis to conclude the client was redirected to a captive portal for authentication.