N10-009 Practice Test 2 — 10 Questions

Question 1

A network engineer is implementing OSPF on a router. All directly connected neighbors are listed with state FULL, but routes from another area are not appearing in the routing table. Which of the following is the most likely cause?

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

Accepted Answer

The router has an ACL blocking inbound OSPF updates. An ACL applied to the OSPF process or interface can filter inbound Type 3 LSAs (summary LSAs) from other areas. Even though neighbor adjacencies reach FULL state, the router will not install those inter-area routes into the routing table if the ACL blocks the LSA updates. This explains why directly connected neighbors are fine but routes from another area are missing.

Answer

The router is not configured with a router ID

Answer

The router is configured as an ABR but does not have a virtual-link configured

Answer

The link-state database is corrupted

Question 2

A company wants to increase the bandwidth between two switches without upgrading the existing 1 Gbps copper links. Both switches support 802.3ad. Which technology should be implemented?

Accepted Answer

Link aggregation (LACP). Link aggregation using LACP (802.3ad) allows multiple 1 Gbps copper links to be combined into a single logical link, increasing bandwidth between the two switches without upgrading the physical interfaces. Since both switches support 802.3ad, they can negotiate and manage the aggregated link dynamically, providing both increased throughput and link redundancy.

Answer

VLAN trunking

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Port mirroring

Answer

StackWise

Question 3

Drag and drop the steps to configure a firewall rule allowing inbound HTTPS traffic to a web server into the correct order.

Accepted Answer

Define rule name & description, then specify protocol and port (TCP/443), then specify source and destination addresses, then set action to allow and apply the rule.. The correct sequence for configuring a firewall rule to allow inbound HTTPS traffic is to start with a descriptive rule name, then specify the protocol (TCP) and port (443) to identify the service, then define the source and destination IP addresses, and finally set the action to allow and apply the rule. This order follows logical firewall policy design: identification, service definition, addressing, and enforcement. Common mistakes include placing the protocol/port after addressing or delaying the rule name, which can lead to disorganized or incorrect firewall configurations.

Answer

Specify protocol and port (TCP/443), then define rule name & description, then specify source and destination addresses, then set action to allow and apply the rule.

Answer

Specify source and destination addresses, then specify protocol and port (TCP/443), then define rule name & description, then set action to allow and apply the rule.

Answer

Define rule name & description, then specify source and destination addresses, then specify protocol and port (TCP/443), then set action to allow and apply the rule.

Question 4

A security analyst notices that the DHCP server is responding to a large number of DHCP Discover messages from a single MAC address, but that client never sends a DHCP Request to complete the lease. This pattern repeats continuously. Which type of attack is most likely occurring?

Accepted Answer

DHCP starvation. The described behavior—a single MAC address sending continuous DHCP Discover messages without completing the lease with a DHCP Request—is the hallmark of a DHCP starvation attack. The attacker exhausts the DHCP server's IP address pool by claiming all available leases, preventing legitimate clients from obtaining IP addresses. This attack targets the DHCP protocol's four-step DORA (Discover, Offer, Request, Acknowledge) process by never completing the handshake.

Answer

ARP poisoning

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DNS amplification

Answer

Rogue DHCP server

Question 5

Which of the following protocols is used to automatically assign IP addresses to devices on a network and also provides the subnet mask and default gateway?

Accepted Answer

DHCP. DHCP (Dynamic Host Configuration Protocol) is the correct answer because it is specifically designed to automatically assign IP addresses to devices on a network, along with essential configuration parameters such as the subnet mask and default gateway. When a DHCP client sends a discover message, the DHCP server responds with an offer that includes these details, allowing the client to fully participate in network communication without manual configuration.

Answer

DNS

Answer

ARP

Answer

ICMP

Question 6

A network administrator wants to collect performance data from network devices over time and receive alerts when thresholds are exceeded. Which protocol should be used?

Accepted Answer

SNMP. SNMP (Simple Network Management Protocol) is designed to collect performance data from network devices by polling MIB (Management Information Base) objects and can generate traps or inform requests to send alerts when thresholds are exceeded. This makes it the correct choice for proactive monitoring and threshold-based alerting.

Answer

syslog

Answer

NetFlow

Answer

ICMP

Question 7

A security engineer is configuring a site-to-site VPN between two branch offices. The requirement is to encrypt all traffic between the two networks using IPsec. Which IPsec mode should be used to encrypt the entire IP packet including the original header?

Accepted Answer

Tunnel mode. Tunnel mode is the correct choice because it encrypts the entire original IP packet, including the original header, and then encapsulates it within a new IP header. This is required for site-to-site VPNs where the original source and destination IP addresses must be hidden or protected, and the new header is used for routing between the two VPN gateways.

Answer

Transport mode

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AH only

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ESP only

Question 8

Which layer of the OSI model is responsible for logical addressing and routing of packets between networks?

Accepted Answer

Network layer. The Network layer (Layer 3) is responsible for logical addressing (e.g., IPv4/IPv6 addresses) and routing packets between different networks by determining the best path using routing protocols such as OSPF, BGP, or static routes. Unlike the Data Link layer, which handles physical addressing (MAC) within a single network segment, the Network layer enables end-to-end delivery across multiple hops.

Answer

Data Link layer

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Transport layer

Answer

Application layer

Question 9

A network administrator reviews firewall logs and sees thousands of SYN packets coming from various source IP addresses to a single internal web server. No ACK or RST packets are observed from these sources. Which type of attack is most likely occurring?

Accepted Answer

SYN flood attack. A SYN flood attack exploits the TCP three-way handshake by sending a high volume of SYN packets to a target server without completing the handshake (no ACK or RST). This exhausts the server's connection table resources, preventing legitimate connections. The observed pattern of many SYN packets from various sources with no subsequent ACK or RST is the hallmark of a SYN flood.

Answer

DNS amplification attack

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ARP spoofing attack

Answer

Man-in-the-middle attack

Question 10

A new switch is installed in a remote wiring closet. It has been configured with a management IP address of 10.1.2.50/24. The switch is connected via a trunk to the distribution switch, and the management station (10.1.1.0/24) is on a different subnet. The switch cannot be pinged from the management station. The distribution switch has routing to the 10.1.2.0/24 subnet. What is the most likely cause?

Accepted Answer

The default gateway is not configured on the new switch.. The management station is on subnet 10.1.1.0/24, while the switch's management IP is 10.1.2.50/24. For the switch to reply to pings from a different subnet, it must have a default gateway configured so it knows where to send return traffic. Without a default gateway, the switch will only respond to traffic on its local subnet, making it unreachable from the management station.

Answer

The management VLAN is not allowed on the trunk.

Answer

The switch port to the distribution switch is in access mode.

Answer

The management IP is configured on the wrong VLAN.