NetSec-Analyst Troubleshooting Practice Test 3 — 15 Questions

Question 1

An administrator is troubleshooting an issue where SSL decryption is failing for a specific web application. The forward proxy is configured correctly, and the certificate is trusted. Users report that they receive certificate errors when accessing the application. Which step should the administrator take to identify why SSL decryption is failing for this application?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Examine the decryption log to see if the session was decrypted and if any errors occurred during the SSL handshake.. The decryption log is specifically designed to record SSL decryption events, including successes and failures. It will indicate if decryption was bypassed, if the certificate was untrusted, or if the application used unsupported features like certificate pinning. This log provides the exact reason for the failure, allowing the administrator to take appropriate action, such as adding the application to a decryption bypass list.

Answer

Check the forward trust certificate and ensure it is installed and trusted by the client devices.

Answer

Run a packet capture on the client to server traffic to analyze the SSL handshake and identify the point of failure.

Answer

Verify that the SSL decryption policy includes the application and that the decryption profile is correctly applied.

Question 2

A network security analyst is troubleshooting an issue where a firewall's management interface is unreachable. The analyst has console access and suspects that the management plane CPU is overloaded. Which CLI command should the analyst use to identify the top processes consuming CPU on the management plane?

Accepted Answer

show processes top. The 'show processes top' command is designed to show real-time CPU usage per process, making it the ideal tool to identify which process is overloading the management plane. It provides a sorted list, so the analyst can quickly spot the top consumer. Other commands show aggregate resource usage or do not exist, making them ineffective for this specific troubleshooting task.

Answer

show system resources

Answer

show management-plane cpu

Answer

show running resource-monitor

Question 3

A network security analyst is troubleshooting an issue where a user cannot access a web application. The analyst runs 'test security-policy-match' and finds that the traffic is being denied by a security policy. The analyst wants to determine which TWO factors could cause the traffic to match a deny rule instead of the intended allow rule. (Choose two.)

Accepted Answer

The source user is not correctly identified, causing the policy to fall through to a deny rule.. The two factors are incorrect source user identification and incorrect application identification. If User-ID fails to identify the user, or App-ID fails to identify the application, the traffic may not match the intended allow rule that specifies those criteria, and instead match a deny rule. These are common issues in policy matching and should be checked first when troubleshooting.

Answer

The security policy rule order is incorrect, with a deny rule placed before the allow rule.

Answer

The service is not correctly defined, causing the policy to match a deny rule.

Answer

The destination security zone is incorrectly configured as 'trust' instead of 'untrust'.

Question 4

A network security analyst is troubleshooting a connectivity issue and needs to verify whether the firewall is receiving packets on a specific interface. Which CLI command should the analyst use to view real-time packet capture on the interface?

Accepted Answer

debug dataplane packet-diag set capture on. The correct command is 'debug dataplane packet-diag set capture on' because it enables packet capture on the dataplane. After setting a filter, this command starts the capture, and the analyst can then view packets with 'debug dataplane packet-diag show capture'. The other options are either for interface status, not real-time capture, or invalid commands.

Answer

tcpdump interface ethernet1/1

Answer

debug dataplane packet-diag set filter match source 10.1.1.1

Answer

show interface ethernet1/1

Question 5

A network security analyst is troubleshooting a site-to-site VPN issue where the tunnel is up, but traffic is not passing. The analyst suspects that the proxy IDs are mismatched. Which CLI command should the analyst use to verify the proxy IDs configured for the VPN tunnel?

Accepted Answer

show vpn ipsec-sa tunnel . The correct command is 'show vpn ipsec-sa tunnel ' because it displays the IPsec security associations, including the proxy IDs negotiated for the tunnel. Proxy ID mismatches are a common reason for a VPN tunnel to be up but not pass traffic. The other commands either show IKE SA details, flow statistics, or are invalid.

Answer

show vpn flow name <tunnel-name>

Answer

show vpn gateway <gateway-name>

Answer

show vpn ike-sa gateway <gateway-name>

Question 6

A network security analyst is troubleshooting an issue where a user cannot reach an external web server through the firewall. The security policy is configured to allow the traffic, and the routing table on the firewall shows a valid default route. The analyst runs a packet capture on the firewall's ingress interface and sees the client's SYN packets arriving, but no SYN-ACK is returned. The analyst suspects the firewall is dropping the packets. Which troubleshooting step should the analyst perform next to determine why the firewall is dropping the packets?

Accepted Answer

Run 'show counter global filter delta yes' to check for global counters indicating drops, such as 'flow_fwd_lookup_fail' or 'nat_policy_drop'.. The firewall receives SYN packets but does not forward them, indicating a drop before session establishment. Global counters track drop reasons in real time, such as routing lookup failures or NAT policy drops. Checking these counters with a delta filter reveals what happened to the packets during the troubleshooting window. This approach directly identifies the drop cause, unlike policy matching or session details, which are more useful when sessions exist or policies are suspect.

Answer

Run 'test security-policy-match' from the CLI to verify which security policy is matching the session.

Answer

Use 'show routing route' to verify the default route is active and correct.

Answer

Check the session details with 'show session all filter source destination ' to view the session's drop reason.

Question 7

A network security analyst is troubleshooting a connectivity issue where a client cannot access a server across a VPN tunnel. The analyst runs a packet capture on the firewall's tunnel interface and sees that packets are being sent into the tunnel, but no packets are received back. The analyst suspects that the remote peer is not receiving or processing the packets. Which tool should the analyst use to verify whether the packets are being encrypted and sent out correctly?

Accepted Answer

show vpn flow. The 'show vpn flow' command provides per-flow statistics, including the number of packets encrypted and decrypted. If the analyst observes that encrypted packets are increasing while decrypted packets remain zero, it indicates that the local firewall is sending traffic into the tunnel but not receiving any return traffic. This confirms that the remote peer is not responding or not processing the packets, narrowing down the troubleshooting to the remote end or the return path.

Answer

show vpn ipsec-sa

Answer

show session all filter application ipsec-esp

Answer

show vpn ike-sa

Question 8

A user reports that they cannot access a website, receiving a 'page cannot be displayed' error. Which log type should the administrator check first to see if the traffic is reaching the firewall?

Accepted Answer

Traffic Log. The Traffic log tracks every session that hits the firewall, making it the primary source for connectivity troubleshooting.

Answer

System Log

Answer

URL Filtering Log

Answer

Threat Log

Question 9

An administrator notices high CPU usage on the management plane. Which command should be used to identify which process is causing the load?

Accepted Answer

show system resources. The 'show system resources' command provides a real-time view of CPU and memory utilization per process.

Answer

debug dataplane packet-diag

Answer

show system statistics

Answer

show system info

Question 10

Traffic is failing the 'Service' check in a security policy. Which CLI tool can be used to confirm which application is being identified for a specific source-destination pair?

Accepted Answer

test security-policy-match. The 'test security-policy-match' tool simulates a policy lookup to determine which rule and application-ID will be matched for a given flow.

Answer

debug dataplane packet-diag

Answer

show session all

Answer

show policy rulebase

Question 11

A user reports that they are seeing a 'Server Certificate Warning' when accessing an internal site. Which feature should the administrator investigate?

Accepted Answer

SSL Decryption policy. SSL Forward Proxy decryption issues usually manifest as certificate warnings if the users do not trust the CA that signed the re-signed certificate.

Answer

Security Policy rules

Answer

URL Filtering profile

Answer

App-ID configuration

Question 12

Which log would display an event regarding an administrator logging into the WebUI?

Accepted Answer

System Log. Configuration and administrative access logs are stored in the System log.

Answer

Threat Log

Answer

Config Log

Answer

Traffic Log

Question 13

A firewall is reporting 'Packet buffer protection' drops. What is the most likely cause of this issue?

Accepted Answer

High volume of traffic exceeding processing capacity. Packet buffer protection is triggered when the firewall receives traffic faster than it can process, often due to a DoS attack or massive traffic spike.

Answer

Hardware failure

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License expiration

Answer

Policy misconfiguration

Question 14

An administrator wants to verify that a specific Threat Prevention profile is applied to a security rule. Where is the most accurate place to check this?

Accepted Answer

Policies > Security > [Rule] > Actions. Within the Security Policy rule definitions, each rule has a dedicated 'Actions' tab where the Profile Group or specific profile is mapped.

Answer

Objects > Security Profiles

Answer

Monitor > Threat

Answer

Device > Setup

Question 15

When troubleshooting a connection, an administrator sees 'aged-out' in the session table. What does this indicate?

Accepted Answer

The session timed out due to inactivity. Aged-out means the session was closed by the firewall because no traffic was seen for that session for a duration exceeding the timeout value.

Answer

The session is currently active

Answer

The session was terminated by a TCP RST packet

Answer

The session was blocked by a threat profile