100-150 Standards and Concepts — Timed 10 Questions

Question 1

A network engineer is designing a small branch office and needs to select a subnet mask that provides exactly 62 usable host addresses for a single VLAN. Which CIDR notation should the engineer apply to the network prefix?

10 minute time limit — choose an answer to begin.

Accepted Answer

/26. A /26 subnet mask (255.255.255.192) leaves 6 host bits, yielding 2^6 = 64 total addresses, of which 62 are usable after reserving the network and broadcast addresses. This exactly matches the requirement of 62 usable host addresses for a single VLAN. The /26 prefix is the correct CIDR notation for this design.

Answer

/25

Answer

/27

Answer

/24

Question 2

A technician is observing a network where many devices are experiencing slow performance and frequent packet collisions. Upon inspection, the technician finds that several desktop computers are connected to an old 8-port Ethernet hub. Why would replacing the hub with a switch resolve this issue?

Accepted Answer

A switch breaks the network into multiple collision domains.. While the explanation correctly identifies that switches provide dedicated bandwidth, it incorrectly states that the transition 'eliminates collision domains'. In reality, a switch creates a separate collision domain for each port, rather than eliminating them entirely.

Answer

A switch will provide a unique IP address to each device automatically.

Answer

A switch uses CSMA/CD to manage traffic more effectively than a hub.

Answer

A switch converts the electrical signals into optical signals for faster speed.

Question 3

Which THREE of the following are considered advantages of the IPv6 protocol over IPv4? (Choose three.)

Accepted Answer

Larger address space. While IPsec was originally designed to be a mandatory component of IPv6 in RFC 2460, this requirement was removed in the updated IPv6 specification (RFC 8200). IPsec is now optional for IPv6, just as it is for IPv4. The other two options (Larger address space and Simplified header structure) are correct, but the inclusion of 'Mandatory IPsec' as a correct answer is factually outdated and misleading for a modern networking exam.

Answer

Broadcast-based address resolution

Answer

Mandatory IPsec implementation

Answer

Compatibility with IPv4 hardware

Question 4

A network architect is evaluating IPv6 address types for a new deployment. The architect needs to identify which TWO IPv6 address types are used for one-to-many communication, where a single packet is sent to multiple destinations. (Choose two.)

Accepted Answer

Anycast. Multicast and anycast are the two IPv6 address types that support one-to-many communication. Multicast delivers a single packet to multiple interfaces that have joined a multicast group. Anycast delivers a packet to the nearest interface among a group of interfaces sharing the same anycast address. Both are essential for IPv6 operations and replace the broadcast concept from IPv4.

Answer

Unicast

Answer

Link-local

Answer

Broadcast

Question 5

A technician is installing a new wireless access point in a small office. The office uses a private IPv4 addressing scheme. The technician needs to assign an IP address to the access point's management interface. Which of the following IP addresses is a private IPv4 address that can be used without conflicting with public internet addresses?

Accepted Answer

192.168.1.1. The private IPv4 address ranges are 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16. Among the options, 192.168.1.1 is a valid private address commonly used for management interfaces. 172.15.1.1 is public, 224.0.0.1 is multicast, and 10.0.0.1 is also private but the question likely expects the most typical choice for a small office access point, which often defaults to 192.168.1.1.

Answer

10.0.0.1

Answer

172.15.1.1

Answer

224.0.0.1

Question 6

A network engineer is comparing IPv4 and IPv6 header fields. The engineer needs to identify two fields that are present in the IPv6 header but not in the IPv4 header. Which two fields are these? (Choose two.)

Accepted Answer

Flow Label. The IPv6 header introduces the Flow Label and Next Header fields, which are not present in IPv4. The Flow Label is used for flow identification, and the Next Header replaces the Protocol field but is more versatile, supporting extension headers. Traffic Class, Payload Length, and Hop Limit have counterparts in IPv4 (ToS, Total Length, TTL), so they are not unique to IPv6.

Answer

Payload Length

Answer

Traffic Class

Answer

Hop Limit

Question 7

A network administrator is troubleshooting a connectivity issue between two hosts on the same IPv4 subnet. Host A has IP address 192.168.10.10/24 and Host B has 192.168.10.20/24. Host A can ping Host B, but Host B cannot ping Host A. The administrator checks the ARP cache on both hosts and finds that Host B has an entry for Host A, but Host A has no entry for Host B. What is the most likely cause?

Accepted Answer

Host A has a static ARP entry or ARP cache issue that prevents it from learning Host B's MAC address.. Host B can ping Host A because it has a valid ARP entry for Host A and can send frames to it. Host A cannot ping Host B because it lacks an ARP entry for Host B, likely due to a static ARP entry or cache problem. Correcting Host A's ARP cache should restore bidirectional connectivity.

Answer

Host A has an incorrect default gateway, so it cannot reply to Host B's ARP request.

Answer

Host A has a firewall rule blocking ICMP echo replies from Host B.

Answer

Host B has an incorrect subnet mask, causing it to send ARP requests for Host A to the wrong subnet.

Question 8

A network technician is troubleshooting a connectivity issue where a workstation can communicate with local devices but cannot access any resources on a different subnet. After verifying the IP address and subnet mask, which component should be investigated next to ensure the packet can leave the local segment?

Accepted Answer

The default gateway address configured on the workstation.. The default gateway is the router interface that forwards packets destined for remote subnets. If the workstation's default gateway is missing, incorrect, or unreachable, the packet cannot leave the local segment even though local communication works. Since IP and subnet mask are verified, the next logical check is the gateway configuration.

Answer

The MAC address table of the local access switch.

Answer

The physical layer integrity of the crossover cable.

Answer

The DNS server settings for name resolution.

Question 9

An organization is upgrading its cabling infrastructure to support Gigabit Ethernet over a distance of 85 meters. Which twisted-pair cable category is the minimum requirement to reliably support 1000 Mbps speeds at this specific distance?

Accepted Answer

Category 5e (Cat5e). Selecting the correct copper cabling category is vital for meeting bandwidth requirements while adhering to distance limitations defined by TIA/EIA standards. Understanding the capabilities of different categories ensures that the network infrastructure can support modern data rates without signal degradation or excessive crosstalk, which could lead to retransmissions and degraded user experiences across the enterprise.

Answer

Category 3 (Cat3)

Answer

Category 5 (Cat5)

Answer

Category 2 (Cat2)

Question 10

Which TWO characteristics distinguish the User Datagram Protocol (UDP) from the Transmission Control Protocol (TCP)?

Accepted Answer

UDP provides connectionless communication without a handshake.. The choice between TCP and UDP is a fundamental architectural decision based on the needs of the application. TCP provides reliability and flow control at the cost of overhead, while UDP prioritizes speed and efficiency. Understanding these differences allows network professionals to troubleshoot performance issues and optimize traffic for different types of data, such as streaming or file transfers.

Answer

UDP uses sequence numbers to reassemble data in the correct order.

Answer

UDP operates at the Network Layer of the OSI model.

Answer

UDP includes a three-way handshake to ensure delivery.