100-150 Practice Test 7 — 10 Questions

Question 1

Which protocol operates at the Application layer of the TCP/IP model and is used to resolve hostnames into IP addresses?

Accepted Answer

DNS. DNS (Domain Name System) operates at the Application layer of the TCP/IP model and is responsible for resolving human-readable hostnames (like www.example.com) into IP addresses. It uses UDP port 53 for standard queries and TCP port 53 for zone transfers and large responses.

Answer

DHCP

Answer

ARP

Answer

HTTP

Question 2

A network administrator needs to ensure that data remains confidential during transit across an untrusted network. Which protocol implementation best addresses this requirement?

Accepted Answer

SSH. SSH (Secure Shell) provides encrypted, authenticated communication over untrusted networks, typically on TCP port 22, using strong cryptographic algorithms to protect data in transit. It replaces insecure remote-access protocols like Telnet by encrypting the entire session, ensuring confidentiality and integrity. This directly satisfies the requirement that data remain confidential during transit.

Answer

Telnet

Answer

HTTP

Answer

SNMPv1

Question 3

Which TWO of the following statements regarding IPv6 address representation are accurate?

Accepted Answer

Leading zeros in a 16-bit field can be omitted.. Option B is correct because RFC 4291 allows leading zeros within any 16-bit hexadecimal field (hextet) to be dropped, so 0db8 can be written as db8. Option D is correct because the double-colon (::) is the compression notation that stands in for one or more consecutive 16-bit groups that are all zeros, and it may appear only once in an address. Option A is wrong because :: can be used only a single time per address; using it twice would make the number of omitted zero groups ambiguous. Option C is wrong because IPv6 addresses are commonly written in compressed form, not always as a full 32-character hexadecimal string. Option E is wrong because only leading zeros may be omitted; trailing zeros are significant and must be retained.

Answer

The double-colon (::) can be used multiple times in a single IPv6 address to shorten it.

Answer

An IPv6 address must always be written in full 32-character hexadecimal format.

Answer

Trailing zeros in a 16-bit field can be omitted.

Question 4

An administrator needs to subnet the 192.168.10.0/24 network into subnets that can support at least 25 hosts each. Which subnet mask provides the maximum number of subnets while meeting the host requirement?

Accepted Answer

255.255.255.224. To support at least 25 hosts, the subnet must have at least 5 host bits (2^5 - 2 = 30 usable hosts). A /27 mask (255.255.255.224) leaves 5 host bits, providing 30 usable addresses per subnet and yielding 8 subnets from a /24. This maximizes subnet count while still meeting the 25-host requirement.

Answer

255.255.255.248

Answer

255.255.255.240

Answer

255.255.255.192

Question 5

A technician is installing a new set of outdoor wireless access points. Which TWO factors are most likely to cause signal attenuation or interference for these endpoints?

Accepted Answer

Thick concrete walls and metal structures. Option A is correct because thick concrete walls and metal structures are dense physical obstructions that absorb, reflect, and scatter RF energy, causing significant signal attenuation, especially at higher frequencies like 5 GHz and 6 GHz. Option C is correct because 2.4 GHz cordless phones and microwave ovens operate in or near the 2.4 GHz ISM band and emit RF energy that overlaps with WLAN channels, producing co-channel and adjacent-channel interference. Option B is not a factor because Category 6a cabling is a wired Ethernet medium for the backhaul and does not radiate or attenuate wireless signals in a way that affects RF propagation. Option D is not a factor because PoE+ (802.3at) is simply a power-delivery standard over Ethernet and does not cause RF attenuation or interference. Option E is not a factor because an LC-to-LC fiber patch cord carries optical signals for wired backhaul and is immune to RF interference and does not affect wireless signal quality.

Answer

The use of Category 6a cabling for the backhaul

Answer

Configuring the access point for PoE+ (802.3at)

Answer

Using an LC-to-LC fiber patch cord

Question 6

What is the primary function of the Spanning Tree Protocol (STP) in a network with redundant links?

Accepted Answer

To prevent Layer 2 loops.. STP's primary function is to prevent Layer 2 loops by creating a loop-free logical topology. In a network with redundant links, STP elects a root bridge, determines root ports and designated ports, and blocks redundant ports to eliminate loops. This prevents broadcast storms and MAC address table instability that would otherwise occur due to frames circulating indefinitely.

Answer

To increase the total bandwidth of multiple links.

Answer

To assign IP addresses to switches.

Answer

To route traffic between different VLANs.

Question 7

Which tool is best suited for identifying a slow network segment caused by excessive broadcast traffic?

Accepted Answer

Protocol analyzer.. Broadcast storms or high volumes of traffic can severely degrade network performance. A protocol analyzer, or network sniffer, allows a technician to capture packets and examine the distribution of traffic types. By looking at the percentage of broadcast traffic compared to unicast traffic, one can identify if a specific segment is being overwhelmed by broadcast frames, which is critical for maintaining network latency and stability.

Answer

Cisco DNA Center.

Answer

SNMP Manager.

Answer

TDR cable tester.

Question 8

A network technician is troubleshooting a PC that cannot access internal network resources. Which TWO steps are recommended to verify if the PC is receiving a valid IP address?

Accepted Answer

Run ipconfig on the workstation.. Verifying the IP configuration is essential when network access fails. Using 'ipconfig' allows the technician to see if the PC has a valid address, subnet mask, and gateway. Checking the DHCP server configuration ensures that the scope is not exhausted and that the client is actually communicating with the server. These two steps confirm if the layer 3 addressing is correct before moving on to more complex layer 2 or routing issues.

Answer

Check the switch interface status.

Answer

Perform a traceroute to the local gateway.

Answer

Reset the switch configuration.

Question 9

A network engineer is troubleshooting a potential DHCP issue. Which THREE components are provided to a client during a successful DHCP 'Acknowledgment' (ACK) message? (Choose three.)

Accepted Answer

IP address for the client.. The DHCP ACK is the final step in the DORA process where the server confirms the lease of an IP address. Understanding the specific parameters delivered in this message is crucial for diagnosing configuration errors that affect host connectivity, name resolution, and the ability of devices to reach resources outside their local network segment.

Answer

The MAC address of the DHCP server.

Answer

The SSH private key for the management console.

Question 10

What is the primary purpose of a default gateway in an IP host configuration?

Accepted Answer

To act as an exit point for off-subnet traffic.. A default gateway is the router that a host sends packets to when the destination IP is not on the local subnet. It serves as the exit point for off-subnet traffic, allowing communication with external networks such as the internet or other subnets.

Answer

To resolve domain names to IP addresses.

Answer

To manage the assignment of dynamic IP addresses.

Answer

To filter incoming traffic from the internet.