PCNSE Core Concepts and Architecture Practice Question
An administrator is reviewing the firewall's session table and notices many sessions in a 'discard' state. What is the most likely cause of this session state?
⚠ Common exam trap
The trap here is assuming 'discard' means the session is waiting for inspection, but it actually means the session is being terminated.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The session was denied by a security policy or a threat was detected and the session was reset.
Sessions in 'discard' state indicate that the firewall has decided to drop the session, usually due to a security policy deny action or a threat detection with a reset or drop action. This state persists until the session times out. Understanding session states helps administrators quickly identify policy violations or security events.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The firewall is experiencing high CPU utilization.
Why it's wrong here
High CPU utilization can affect performance but does not directly cause sessions to be in a 'discard' state. The 'discard' state typically indicates that the firewall has decided to drop the session due to a policy action or threat detection, not resource exhaustion. High CPU might lead to other issues like session timeouts, but it is not the primary cause of discard.
- ✓
The session was denied by a security policy or a threat was detected and the session was reset.
Why this is correct
Sessions in 'discard' state are typically those that have been denied by a security policy or have been reset due to a threat detection. When a security policy denies traffic, the firewall creates a session entry with the action 'deny' and the state may show as 'discard' until the session times out. Similarly, if a threat is detected and the action is 'reset-both' or 'drop', the session is marked for discard.
- ✗
The session is waiting for application identification to complete.
Why it's wrong here
Sessions waiting for application identification are typically in a 'pending' or 'active' state, not 'discard'. App-ID occurs after the session is allowed, and during that time the session is active. If App-ID identifies the application as one that is denied by policy, the session may then be discarded, but the waiting period itself is not 'discard'.
- ✗
The firewall is performing SSL decryption and the session is temporarily paused.
Why it's wrong here
SSL decryption does not cause sessions to enter a 'discard' state. During decryption, sessions are active and may be in a 'decrypt' state, but not 'discard'. The 'discard' state is specifically for sessions that are being terminated or denied, not for those undergoing inspection. SSL decryption is a separate process that occurs before security policy enforcement.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Palo Alto Networks exam blueprint
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