Troubleshooting Scenario Questions

The traffic is being decrypted by an SSL Forward Proxy rule.

Why wrong: Decryption does not cause drops; it may affect identification but not silent drops.

The traffic is matched by a rule with action 'deny' and logging is disabled.

Why wrong: Even with logging disabled, a denied session appears briefly in the session table.

The interzone default rule is set to deny.

Why wrong: Default deny rules log drops, so they would not be silent.

Modify the existing allow rule to include the entire 10.2.0.0/24 subnet in the source.

Why wrong: Modifying the existing rule might not work if there is a deny rule above it still matching.

Change the destination zone of the allow rule to 'any'.

Why wrong: Changing the destination zone is not relevant; the issue is rule order.

Delete the deny rule that is blocking the traffic.

Why wrong: Deleting the deny rule could expose other traffic that should be blocked.

The destination NAT is configured incorrectly.

Why wrong: Destination NAT would not affect outbound sessions; it changes the destination on inbound.

The security policy is missing the return traffic rule.

Why wrong: Security policy is stateful, so return traffic is allowed automatically if the outbound session is allowed.

The firewall is in FIPS mode.

Why wrong: FIPS mode affects encryption, not basic connectivity.

The HA2 link is down.

Why wrong: HA2 is for configuration synchronization; session sync uses HA3.

The passive firewall does not have management API access.

Why wrong: API access is not required for session synchronization.

The logging settings on both firewalls are different.

Why wrong: Logging settings do not affect session synchronization.

Create a security policy rule allowing the traffic between the zones.

Why wrong: Security policy is necessary but does not solve the routing issue.

Configure route redistribution between VR-A and VR-B using a routing protocol.

Why wrong: This would work but is overkill for a single subnet; simpler to add a static route.

Place all interfaces in the same virtual router.

Why wrong: This would break the segmentation that the company wants.

The default SSL/TLS service profile changed, affecting management access.

Why wrong: This would affect management GUI/API, not IPsec tunnels.

The upgrade reset the IKE gateway configuration to default.

Why wrong: Upgrades preserve running configuration; config reset does not occur.

The firewall's management IP address changed during the upgrade.

Why wrong: Management IP is not typically altered by an upgrade.

The passive firewall's routing table is not synchronized.

Why wrong: HA synchronizes routing tables, so this should not be an issue.

The virtual router is not configured to use the virtual IPs.

Why wrong: Virtual IPs are automatically assigned to the virtual router in HA.

The HA configuration does not include the virtual router.

Why wrong: HA synchronizes virtual router configuration between peers.

show session info

Why wrong: This command shows active sessions but does not directly indicate performance bottlenecks.

show log traffic

Why wrong: This command shows traffic logs, which are for historical analysis, not real-time bottleneck identification.

Change the security policy rule to use a different URL Filtering profile.

Why wrong: This could affect other traffic and is not a precise solution.

Disable URL Filtering for that traffic flow.

Why wrong: Disabling URL Filtering weakens security and is not a targeted solution.

Add the website's IP address to the URL Filtering exclude list.

Why wrong: IP-based excludes are not reliable and are not a best practice for specific websites.

HA1 keepalive failure is not detected

Why wrong: HA1 keepalive failure would cause failover if interface down, but not management.

HA2 link monitoring is not enabled

Why wrong: HA2 is for session sync, not failover trigger.

Session synchronization is not complete

Why wrong: Session sync status does not affect failover trigger.

Check HA1 link utilization

Why wrong: HA1 is not used for session sync.

Increase the packet buffer protection threshold

Why wrong: Packet buffer does not affect sync.

Restart the HA process on both firewalls

Why wrong: Restart is disruptive and not diagnostic.

Disable preemption on the active firewall

Why wrong: Preemption does not cause sync failure.

Check the HA2 link session synchronization status

Why wrong: HA2 is for data, not config.

Reboot both firewalls to clear the failure

Why wrong: Not a good first step.

Check the HA1 link status using 'show high-availability state'

Why wrong: HA1 is for control traffic, not session sync.

Enable flow-based routing on both firewalls

Why wrong: Flow-based routing is not related to session sync.

Check that the session synchronization encryption is disabled to reduce latency.

Why wrong: Encryption is optional and does not cause sync failure; disabling it does not resolve the issue.

Validate that the heartbeat hold timer is set to a value greater than the failover delay.

Why wrong: Heartbeat hold timer influences failover timing, not session synchronization.

Confirm that the HA1 link is using the correct IP address and is in the same subnet.

Why wrong: HA1 is used for heartbeat and configuration sync, not session synchronization.

show counter global | match ipsec

Why wrong: Counters show aggregate statistics, not real-time negotiation details.

show log system

Why wrong: System logs may include IKE errors but are less detailed than debug IKE.

debug flow basic

Why wrong: Debug flow basic shows flow table operations, not IKE negotiation.