100-150 Practice Test 10 — 10 Questions

Question 1

What is the primary function of a network switch's 'store-and-forward' switching method?

Accepted Answer

To verify the frame integrity before forwarding. Store-and-forward is a high-integrity switching method where the switch receives the entire frame, verifies its checksum (FCS), and only then forwards it. This approach ensures that corrupted frames are discarded at the switch level, preventing them from propagating across the network. This method is critical for maintaining high reliability in environments where physical layer errors might otherwise cause complex intermittent issues.

Answer

To forward frames as soon as the destination address is read

Answer

To route packets between different IP subnets

Answer

To provide high-speed connections for wireless access

Question 2

Which THREE fields are found in the standard IPv4 header and are directly related to the delivery or identification of the packet across subnets?

Accepted Answer

Source IP Address. The IPv4 header contains several fields essential for routing and delivery. The Source IP Address and Destination IP Address are used by routers to make forwarding decisions. The Time to Live (TTL) field prevents packets from looping infinitely by decrementing at each hop, ensuring the network remains stable during convergence.

Answer

MAC Address

Answer

Sequence Number

Question 3

Which TWO protocols are commonly used to retrieve email from a remote server to a local mail client?

Accepted Answer

Post Office Protocol version 3 (POP3). Email retrieval protocols allow users to access their messages stored on a central server. POP3 and IMAP4 are the industry standard protocols for this task, each offering different levels of synchronization and storage management. Understanding these protocols is essential for configuring client devices and troubleshooting mail delivery issues in a corporate or personal network environment.

Answer

Simple Mail Transfer Protocol (SMTP)

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Hypertext Transfer Protocol (HTTP)

Answer

File Transfer Protocol (FTP)

Question 4

A company wants to prevent unauthorized individuals from entering the server room by following closely behind an employee. Which physical security control is specifically designed to address this risk?

Accepted Answer

Mantrap. Physical security is the first line of defense for any organization. It protects the hardware and infrastructure that host critical data and services. Controls like mantrap systems and security guards are used to manage human access to sensitive areas. Understanding these physical measures is as important as knowing logical security for comprehensive protection.

Answer

Biometric scanner

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Video surveillance (CCTV)

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Proximity card reader

Question 5

An administrator wants to ensure that only legitimate DHCP servers provide IP addresses to clients on the network. Which feature should be enabled?

Accepted Answer

DHCP Snooping. Rogue DHCP servers can be used to launch man-in-the-middle attacks by providing clients with malicious gateway addresses. DHCP Snooping creates a distinction between trusted and untrusted ports. By designating only ports connected to authorized servers as trusted, the network automatically blocks DHCP response traffic from unauthorized sources. This is essential for maintaining control over the network's address allocation process and preventing redirection of user traffic.

Answer

Port Security

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Dynamic ARP Inspection

Answer

IP Source Guard

Question 6

Refer to the exhibit. An engineer observes that the interface status for Vlan100 is listed as 'up' but the protocol status is 'down'. What is the most likely root cause of this operational state?

Accepted Answer

No active physical access ports exist within that VLAN, or all assigned ports are currently in the spanning-tree blocking state.. An interface protocol state of down while the physical or logical status is up indicates that Layer 2 or higher encapsulation parameters are failing. For a Switched Virtual Interface, this typically occurs when no active physical ports are assigned to that VLAN or when all assigned access ports are currently in a blocked or disabled state.

Answer

The SVI administrative configuration contains a mismatched IP subnet mask compared to the connected default gateway.

Answer

The global routing command has not been enabled on the multilayer switch using the ip routing configuration command.

Answer

The physical transceiver connected to GigabitEthernet0/1 has experienced a complete hardware optical laser failure.

Question 7

While monitoring a network, an administrator sees a sudden spike in CPU usage on all switches and very high levels of broadcast traffic. What is the most likely cause of this behavior?

Accepted Answer

A Layer 2 loop in the topology.. A switching loop occurs when there are multiple active paths between switches without Spanning Tree Protocol (STP) preventing a loop. This causes broadcast frames to circulate endlessly, multiplying and consuming all available bandwidth and CPU resources. This 'broadcast storm' is a critical Layer 2 failure that can bring down an entire network.

Answer

A malfunctioning DHCP server.

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An IP address conflict on the gateway.

Answer

The use of the 'traceroute' command by a user.

Question 8

A network administrator is using the 'ping' command to troubleshoot connectivity. Which TWO pieces of information can be determined specifically from the ICMP Echo Reply messages? (Choose two.)

Accepted Answer

The approximate round-trip time between source and destination.. The ping utility is a fundamental tool for verifying Layer 3 reachability. It provides critical diagnostic data such as round-trip time and packet loss statistics. Understanding how to interpret ping results allows technicians to distinguish between complete outages, intermittent physical issues, and potential congestion or routing delays within the network path.

Answer

The specific MAC address of the destination device.

Answer

The list of every router hop along the path.

Answer

The TCP port numbers that are currently open on the host.

Question 9

Refer to the exhibit. What is the expected behavior if a second device with a different MAC address is plugged into this port?

Accepted Answer

The port will move to err-disabled state.. The 'shutdown' violation mode triggers an immediate err-disable state on the interface when a security violation occurs. By setting the maximum to 1 and using sticky MAC learning, the switch locks the first learned address. A second device triggers the security policy, disabling the port to protect the network. This mechanism is vital for stopping unauthorized device connections, forcing administrators to manually re-enable the port after investigating the potential security breach.

Answer

The port will remain up and drop the traffic.

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The port will alert the console but stay active.

Answer

The switch will replace the existing MAC.

Question 10

A technician notices a laptop has an IP address of 169.254.11.45. The laptop cannot access the internet or local servers. What is the most likely cause of this issue?

Accepted Answer

The DHCP server is unreachable or the scope is full.. The 169.254.0.0/16 range is reserved for Automatic Private IP Addressing (APIPA), which is used when a device is configured for DHCP but cannot reach a server. This diagnostic indicator points directly to a failure in the DORA process. Identifying APIPA addresses helps technicians quickly narrow down connectivity issues to the DHCP server or local cabling.

Answer

The laptop has a duplicate IP address on the network.

Answer

The DNS server is currently offline.

Answer

The subnet mask is incorrectly configured manually.