Network+ Review Prep

Front

Which layer of the OSI model is responsible for data encryption and decryption? Options: Physical Layer, Data Link Layer, Presentation Layer, Network Layer

Back

Presentation Layer

Answer explanation

The Presentation Layer is responsible for data encryption and decryption, ensuring that data is securely transmitted and can be understood by the receiving application. This layer formats and encrypts data for the application layer.

Front

What is the primary function of the Network Layer in the OSI model?

Back

Path determination and logical addressing

Answer explanation

The primary function of the Network Layer is path determination and logical addressing, which enables data to be routed across different networks. This is essential for establishing communication between devices on a network.

Front

Convert the binary IP address 11000000.10101000.00000001.00000001 to decimal format.

Back

192.168.1.1

Answer explanation

To convert the binary IP 11000000.10101000.00000001.00000001 to decimal, convert each octet: 11000000 = 192, 10101000 = 168, 00000001 = 1, 00000001 = 1. Thus, the decimal format is 192.168.1.1.

Front

Which of the following is a valid IPv4 address? 256.100.50.25, 192.168.0.256, 192.168.1.1, 192.168.1.1.1

Back

192.168.1.1

Answer explanation

The valid IPv4 address must have four octets, each ranging from 0 to 255. '192.168.1.1' meets this criterion, while the other options either exceed the range or have an incorrect format.

Front

Calculate the number of subnets created by the subnet mask 255.255.255.224.

Back

8

Answer explanation

The subnet mask 255.255.255.224 has 3 bits for subnetting (224 = 11100000 in binary). The number of subnets is 2^3 = 8. Therefore, the correct answer is 8.

Front

What is the subnet mask for a Class C network?

Back

255.255.255.0

Answer explanation

The subnet mask for a Class C network is 255.255.255.0. This allows for 256 IP addresses in the subnet, with 254 usable for hosts, making it suitable for small networks.

Front

Which protocol is used to find the hardware address of a local device?

Back

ARP

Answer explanation

ARP (Address Resolution Protocol) is used to map IP addresses to hardware addresses (MAC addresses) on a local network, making it the correct choice for finding the hardware address of a local device.

Front

Explain how the TCP three-way handshake works.

Back

SYN, SYN-ACK, ACK

Answer explanation

The TCP three-way handshake establishes a connection using three steps: 1) The client sends a SYN packet to initiate the connection. 2) The server responds with a SYN-ACK packet. 3) The client sends an ACK packet to complete the handshake.

Front

Which protocol is used for sending email messages?

Back

SMTP

Answer explanation

The Simple Mail Transfer Protocol (SMTP) is specifically designed for sending email messages. Other protocols like FTP, HTTP, and SNMP serve different purposes, making SMTP the correct choice for email transmission.

Front

What is the main purpose of a router in a network?

Back

To forward data packets between different networks

Answer explanation

The main purpose of a router is to forward data packets between different networks, enabling communication between devices on separate networks. This distinguishes it from switches, which connect devices within the same network.