Subnets in the VPC

Question 1

True or false: AWS automatically create a Virtual Private Cloud (VPC) for each account.

Answer 1

True.

Question 2

What are the default Virtual Private Cloud (VPC) subnets?

Answer 2

The default VPC includes six subnets pre-configured by AWS with each subnet residing in a different availability zone, giving high availability to resources within the VPC.

Question 3

What does 172.31.0.0 indicate?

Answer 3

The first 16 bits (172 and 31) are fixed for network identification and the remaining 16 bits are available for subnets and hosts within those subnets.

Question 4

How do you create additional subnets?

Answer 4

IPv4 Subnetting, which takes a large range (like 172.31.0.0/16) and subdivides it into smaller chunks for different use cases, such as isolating resources or limiting the number of hosts in a subnet.

Question 5

What is a subnet mask?

Answer 5

A 32-bit number used to divide an IP address into network and host proportions.

Question 6

What is a network prefix?

Answer 6

A network prefix specifies the portion of the address used to identify the network itself, while the remaining bits identify hosts within that network.

Question 7

Given 172.31.0.0/20, which bits are used for the network, which are the host bits and how many possible host addresses can be created.

Answer 7

1) 20 bits are used for the network.

2) Subtract the network bits from 32 to calculate the host bits. 32 - 20 = 12 bits for hosts.

3) 2 ^ 12 = 4096 possible host addresses in the subnet.

Question 8

How do you calculate address space in subnets?

Answer 8

Subtract the prefix length from 32 to find the host bits.

Calculate the number of possible addresses by raising 2 to the power of the number of host bits.