Which layer of the OSI model is responsible for data encryption?

• A. Presentation

• B. Session

• C. Network

• D. Data Link

You have been hired by a company that uses a topology shown below. In looking at the physical layout of your network, which of the following types of topologies is being used?

• A. Bus

• B. Star

• C. Mesh

• D. Ring

You are designing a 1000Base-T network. In creating this network, what distance limitation will you be facing when installing the cabling?

• A. 100 m

• B. 185 m

• C. 500 m

• D. 2 km

Which service listed below is used to resolve IP addresses and domain names?

• A. DNS

• B. DHCP

• C. ARP

• D. TCP

Identify the class of IP Address for the following IP address 114.101.101.101?

• A. Class A

• B. Class B

• C. Class C

• D. Class D

Answer explanation

To identify the class of an IP address, check the first octet (the first number in the IP address):

1. Class A: First octet ranges from 1 to 126

2. Class B: First octet ranges from 128 to 191

3. Class C: First octet ranges from 192 to 223

4. Class D: First octet ranges from 224 to 239 (used for multicast)

The IP address 114.101.101.101 has a first octet of 114, which falls in the range of Class A.

Which example is a network adapter loopback address?

• A. 255.0.0.1

• B. 192.0.0.1

• C. 127.10.20.30

• D. 10.0.0.1

Answer explanation

Analysis of the options:

• A. 255.0.0.1: This is an invalid IP address (255 is reserved for broadcast, not loopback).

• B. 192.0.0.1: This is a valid IPv4 address but does not fall in the loopback range.

• C. 127.10.20.30: This falls in the loopback range 127.0.0.0 - 127.255.255.255.

• D. 10.0.0.1: This is part of the private IP address range but is not a loopback address.

Which example below is the default subnet mask of Class B (IP Version 4)?

• A. 255.255.255.224

• B. 255.255.255.0

• C. 255.255.0.0

• D. 255.0.0.0

Answer explanation

Analysis of the options:

• A. 255.255.255.224: This is a custom subnet mask, not the default for any class.

• B. 255.255.255.0: This is the default subnet mask for Class C.

• C. 255.255.0.0: This is the correct default subnet mask for Class B.

• D. 255.0.0.0: This is the default subnet mask for Class A.

Your network has 10 computers that are networked together using a star topology. Which of the following is a possible point of failure for this topology, which could bring down the entire network?

• A. Cable

• B. Network card

• C. T-Connector

• D. Hub

The network layer protocol of the internet is:

• A. ethernet

• B. internet protocol

• C. hypertext transfer protocol

• D. user datagram protocol

You are the network administrator of a 10BaseT network. On the weekend, when a few people are working, you run 110 m of cable to a new server that is being used as a file server. The cable is installed in a new section of the building, where no cabling currently exists. When you attempt to access files on the server, they are experiencing errors and corrupt data. Which of the following is most likely the cause of this problem?

• A. Bandwidth

• B. Attenuation

• C. Crosstalk from a neighboring cable

• D. CSMA/CD issues