Networking Concepts and OSI Model

In the OSI model, which layer is responsible for ensuring reliable host-to-host communication through protocols like TCP and UDP?

A network administrator is troubleshooting connectivity issues and needs to determine the physical path a packet takes to reach a destination. Which OSI layer is MOST relevant for diagnosing routing problems?

Which of the following BEST describes the primary function of a firewall in a network?

Which OSI model layer is primarily concerned with transforming data into a format that another application layer can understand, including handling encryption and decryption?

A network engineer needs to configure a system to resolve human-readable domain names to IP addresses. Which service or protocol should be configured?

Consider an IPv4 address represented in binary form: 11000000 00000000 00000010 00000000. What is the equivalent dotted decimal representation?

Which layer of the OSI model is responsible for defining the physical characteristics of the network, such as voltage levels, data rates, and physical connectors?

An organization has multiple VPCs and wants to establish a direct private connection between them to share resources. Which AWS service or feature would be the MOST suitable for achieving this, ensuring that traffic does not traverse the public internet?

A network engineer needs to configure a highly available and fault-tolerant VPN connection between their on-premises data center and AWS. Which of the following design considerations would BEST contribute to achieving this?

An application hosted on an EC2 instance in a private subnet needs to securely access an AWS service that does NOT have a public endpoint, such as S3 or DynamoDB. Which AWS service or configuration would BEST facilitate this secure access without exposing the application to the internet?

An organization is using AWS Site-to-Site VPN to connect their on-premises network to their VPC. They need to ensure that only traffic originating from a specific subnet in their on-premises network (192.168.10.0/24) can access resources in a specific subnet in their VPC (10.0.2.0/24). What is the MOST effective way to achieve this?

A company's security policy mandates that all traffic between their on-premises data center and AWS VPC must be encrypted. They are using AWS Site-to-Site VPN. Which of the following configurations will BEST satisfy this requirement?

A network engineer is tasked with designing a highly available application across multiple availability zones within an Amazon VPC. How should the engineer configure subnets to ensure proper fault tolerance and network isolation?

An organization requires strict network isolation for its development, testing, and production environments in AWS. What is the MOST effective approach to achieve this using Amazon VPCs?

A company has a VPC with a CIDR block of 10.0.0.0/16 and needs to create four equal-sized subnets. What is the CIDR block range for each subnet?

A network administrator is troubleshooting connectivity issues between two EC2 instances within the same VPC but in different subnets. Which of the following could be a potential cause of the problem?

A company wants to ensure that all traffic from their VPC to the internet goes through a centralized inspection point for security purposes. What is the MOST appropriate way to achieve this in AWS?

An organization is setting up a new VPC and needs to control the inbound and outbound traffic at the subnet level. Which AWS service should they use to achieve this?

A network engineer is designing a VPC for a highly regulated industry and requires detailed logs of all network traffic for compliance purposes. Which AWS service can provide this functionality?

A company wants to extend its on-premises network into AWS using a VPN connection. Which AWS resource is required to establish this connection on the AWS side?

A company needs to allow EC2 instances in a private subnet to access the internet for software updates, but they do not want these instances to be directly accessible from the internet. Which of the following is the MOST secure and cost-effective solution?

A development team is deploying a new application in a VPC and needs to ensure that only specific IP addresses from their corporate network can access the application servers. Which AWS service should they use to implement this restriction?

Given an IPv4 address of 172.16.5.20/18, which of the following statements accurately describe its classification and network size?

A network engineer needs to configure a subnet to accommodate 500 hosts while minimizing wasted addresses. Which CIDR block provides the most appropriate balance?

A router receives a packet with a destination IP address of 192.168.2.15. Its routing table contains the following entries:

192.168.2.0/24 via Interface A

192.168.2.0/28 via Interface B

0.0.0.0/0 via Gateway C

Which interface will the router use to forward the packet?

Which of the following scenarios would necessitate a router to perform subnetting or supernetting?

A network administrator configures a router with a static route to a specific destination network. Under what circumstances would this static route NOT be used?

Consider a scenario where a packet is sent from a host on Subnet A to a host on Subnet B, traversing a router. Which of the following statements is correct regarding the MAC addresses?

Which of the following is the most accurate description of the primary function of a router in a modern network?

An organization has the IP address block 192.168.10.0/24 and needs to create four subnets of equal size. Which subnet mask would accomplish this?

Why is understanding IPv4 address classes (A, B, C) less critical in modern network design compared to when they were initially defined?

A company requires a static public IPv4 address that persists across instance failures and can be remapped to different EC2 instances. Which AWS service should they use?

In a VPC with a CIDR block of 10.0.0.0/16, subnets are created with a /24 CIDR block. Considering the reserved IP addresses, what is the maximum number of usable IP addresses available for assignment to instances within each subnet?

An organization is designing its VPC and requires multiple subnets. They decide to use a CIDR block of 10.0.0.0/16 for the VPC. Which of the following subnet CIDR blocks is invalid and cannot be used within this VPC?

A company has a web application running on EC2 instances within a VPC. They want to ensure that these instances always have the same public IP address, even after the instances are stopped and started. Which approach should they take?

A network engineer is planning the IP address scheme for a new VPC. The VPC is assigned a CIDR block of 10.0.0.0/16. Which of the following is a valid CIDR block that can be assigned to a subnet within this VPC?

An organization needs to create a highly available architecture where an application can rapidly recover from EC2 instance failures. They decide to use Elastic IP addresses. What is the key benefit of using Elastic IP addresses in this scenario?

A company is launching a new application in AWS and requires a public IP address for an EC2 instance. They do not explicitly assign an Elastic IP address. Under what conditions will the EC2 instance receive a public IP address?

A network administrator discovers that instances in a subnet are unable to communicate with the Internet. The route table for the subnet directs all traffic (0.0.0.0/0) to an Internet Gateway. Considering the reserved IP addresses, what is the most likely cause?

Your VPC has a CIDR block of 10.0.0.0/16, and you've created several subnets within it. You need to ensure that instances in one of the subnets (10.0.1.0/24) can be reached from the internet. Which of the following configurations is required?

A company is planning its VPC architecture and needs to decide between using automatically assigned public IP addresses and Elastic IP addresses for its EC2 instances. What is a key difference that should drive their decision?

What is DNS?

What is a Firewall?

What is the OSI model?

What does the Transport layer do?

What is the function of the Network Layer?

What does the Data Link layer do?

What happens in the Physical Layer?

Route Table

Route

Local Route

Subnet-Route Table Association

Amazon VPC

VPC Control

VPC Isolation

VPC Span

Subnet

Subnet Characteristics

Elastic Network Interface

Default Network Interface

AWS Site-to-Site VPN

Virtual Gateway (VGW)

IPv4 Address Classes

CIDR Notation

Routing Table

Class A Range

Class B Range

Class C Range

Host Identifier

Usable IP Addresses in a /24 Subnet

Elastic IP Address

Network Address

Network Broadcast Address

Internal Communication Address

Domain Name System (DNS) Address

Auto-Assign Public IPv4 Address

Elastic IP Address Characteristics

Subnet IP Range

Virtual Private Cloud (VPC)