N10-009 Practice Test 5 — 10 Questions

Question 1

A network engineer is designing a new IPv6 addressing scheme. The company has been assigned a /48 prefix and needs to support up to 250 subnets. Which subnet size should be used to minimize waste while meeting the requirement?

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

Accepted Answer

/56. A /56 subnet provides 256 subnets (2^(56-48) = 2^8 = 256), which meets the requirement of up to 250 subnets with minimal waste. A /48 prefix is the site-level allocation, and using a /56 subnet mask leaves 8 bits for subnetting, offering exactly the needed capacity without over-allocating address space.

Answer

/52

Answer

/64

Answer

/60

Question 2

A network administrator configures a router to send syslog messages to a central log server. The administrator can ping the server from the router, but the server is not receiving any logs. What is the most likely cause?

Accepted Answer

UDP port 514 is blocked between the router and the server. Syslog messages are sent via UDP port 514 by default. Since the administrator can ping the server (ICMP works), but no logs arrive, the most likely cause is that a firewall or ACL is blocking UDP port 514 between the router and the server. This is a classic connectivity issue where Layer 3 reachability exists but the specific transport-layer port is filtered.

Answer

The syslog server is using the wrong protocol (TCP instead of UDP)

Answer

The syslog service on the server is not running

Answer

The router's clock is not synchronized with the server

Question 3

A network administrator is designing a small office network with 40 workstations. The design must ensure that a single cable failure only affects the connected workstation. Which logical topology should the administrator implement?

Accepted Answer

Star. A star topology connects each workstation directly to a central switch or hub, so a cable failure only affects the single connected workstation, not the rest of the network. This meets the requirement for fault isolation at the workstation level, which is the core design goal in a small office with 40 devices.

Answer

Ring

Answer

Bus

Answer

Mesh

Question 4

A network administrator is configuring Quality of Service (QoS) on a router to prioritize voice traffic. Which of the following fields should be used to mark packets for classification and prioritization?

Accepted Answer

DSCP. DSCP (Differentiated Services Code Point) is the correct field because it is a 6-bit value in the IP header used to mark packets for QoS classification and prioritization, as defined in RFC 2474. Voice traffic typically uses DSCP EF (Expedited Forwarding, value 46) to ensure low latency and jitter, making it the standard choice for QoS marking on routers.

Answer

Source IP address

Answer

Source port number

Answer

MAC address

Question 5

A network administrator is configuring a monitoring system to collect metrics from network devices. The administrator needs to ensure that the monitoring system can automatically discover the devices and obtain detailed information about their configuration and status, such as interface descriptions and software versions. Which protocol is best suited for this purpose?

Accepted Answer

SNMP. SNMP (Simple Network Management Protocol) is the correct choice because it is specifically designed for network management and monitoring. It allows a management system to automatically discover devices (via SNMP walks or queries to MIBs) and retrieve detailed configuration and status information, such as interface descriptions and software versions, by reading OIDs from the device's MIB. This matches the requirement for automatic discovery and detailed data collection.

Answer

LLDP

Answer

NetFlow

Answer

Syslog

Question 6

A network administrator wants to prevent unauthorized devices from being plugged into switch ports. Only devices with specific MAC addresses should be allowed on each port. Which switch security feature should be enabled?

Accepted Answer

Port security. Port security is the correct feature because it allows the administrator to restrict which MAC addresses can communicate through a switch port. By configuring allowed MAC addresses (sticky or static), any device with an unknown MAC address attempting to send traffic will trigger a security violation (shutdown, restrict, or protect). This directly addresses the requirement to prevent unauthorized devices from being plugged into switch ports.

Answer

DHCP snooping

Answer

Dynamic ARP inspection

Answer

802.1X

Question 7

Two routers are configured with OSPF in the same area, but they do not form an adjacency. Router A shows OSPF state EXSTART, and Router B shows state EXSTART. Which of the following is the most likely cause?

Accepted Answer

The MTU is mismatched between the two routers. When OSPF routers are stuck in the EXSTART state, it indicates that they have progressed past the 2-Way and ExStart phases but are unable to exchange Database Description (DBD) packets. The most common cause is an MTU mismatch, because OSPF will not proceed to the Exchange state if a DBD packet exceeds the interface MTU of the neighbor. This causes the routers to continuously renegotiate the master/slave relationship without completing the exchange.

Answer

The OSPF Hello and Dead intervals are mismatched

Answer

The OSPF area IDs are different

Answer

The network type is misconfigured (e.g., one side is broadcast, the other is point-to-point)

Question 8

A network administrator needs to power IP phones and wireless access points through the Ethernet cable. Which standard should be supported?

Accepted Answer

802.3af. The 802.3af standard, also known as Power over Ethernet (PoE), delivers up to 15.4 watts of DC power over twisted-pair Ethernet cabling. This allows devices like IP phones and wireless access points to receive both data and power through a single Ethernet cable, eliminating the need for separate power supplies.

Answer

802.11ac

Answer

802.1X

Answer

802.3ab

Question 9

A network administrator wants to prevent rogue DHCP servers from offering IP addresses to clients on the network. Which security feature should be enabled on the switches?

Accepted Answer

DHCP snooping. DHCP snooping is the correct security feature because it acts as a firewall between untrusted hosts and trusted DHCP servers. It validates DHCP messages by filtering out responses from unauthorized DHCP servers on untrusted ports, preventing rogue servers from offering IP addresses to clients. This is achieved by building and maintaining a DHCP snooping binding database that tracks valid IP-to-MAC address mappings.

Answer

Dynamic ARP Inspection (DAI)

Answer

Port Security

Answer

IP Source Guard

Question 10

A security administrator discovers that an attacker has intercepted data between two legitimate hosts by redirecting traffic through a rogue device. Which type of attack is this?

Accepted Answer

Man-in-the-middle. This is a classic man-in-the-middle (MITM) attack, where the attacker intercepts and potentially alters communication between two legitimate hosts by inserting a rogue device into the data path. The key characteristic is the redirection of traffic through the attacker's device, which allows them to capture, inspect, or modify packets in transit.

Answer

ARP poisoning

Answer

DNS poisoning

Answer

Replay attack