Public vs private subnets in AWS - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a public subnet with automatic public IP assignment.

AWS

resource "aws_subnet" "public" {
  vpc_id            = aws_vpc.main.id
  cidr_block        = "10.0.1.0/24"
  map_public_ip_on_launch = [1]
  availability_zone = "us-east-1a"
}

Drag options to blanks, or click blank then click option'

Atrue

B"true"

Cnull

Dfalse

Attempts:

3 left

💡 Hint

Common Mistakes

Using a string "true" instead of boolean true

Setting map_public_ip_on_launch to false for a public subnet

Setting map_public_ip_on_launch to true enables automatic public IP assignment for instances in the subnet, making it public.

2fill in blank

medium

Complete the code to create a route in the public subnet's route table that directs internet traffic to the internet gateway.

AWS

resource "aws_route" "public_internet_access" {
  route_table_id         = aws_route_table.public.id
  destination_cidr_block = "0.0.0.0/0"
  [1]              = aws_internet_gateway.main.id
}

Drag options to blanks, or click blank then click option'

Anat_gateway_id

Binternet_gateway_id

Cgateway_id

Degress_gateway_id

Attempts:

3 left

💡 Hint

Common Mistakes

Using nat_gateway_id instead of gateway_id for internet gateway

Using incorrect attribute names like internet_gateway_id

The correct attribute to specify the internet gateway in a route is gateway_id.

3fill in blank

hard

Fix the error in the private subnet route table to route internet traffic through the NAT gateway.

AWS

resource "aws_route" "private_nat_gateway" {
  route_table_id         = aws_route_table.private.id
  destination_cidr_block = "0.0.0.0/0"
  [1]              = aws_nat_gateway.main.id
}

Drag options to blanks, or click blank then click option'

Agateway_id

Bnat_gateway_id

Cinternet_gateway_id

Degress_gateway_id

Attempts:

3 left

💡 Hint

Common Mistakes

Using gateway_id instead of nat_gateway_id for NAT gateway route

Confusing internet gateway with NAT gateway

For private subnets, internet traffic is routed through the NAT gateway using the nat_gateway_id attribute.

4fill in blank

hard

Fill both blanks to create a private subnet without automatic public IP assignment and associate it with the private route table.

AWS

resource "aws_subnet" "private" {
  vpc_id                  = aws_vpc.main.id
  cidr_block              = "10.0.2.0/24"
  map_public_ip_on_launch = [1]
  availability_zone       = "us-east-1b"
}

resource "aws_route_table_association" "private_assoc" {
  subnet_id      = aws_subnet.private.id
  route_table_id = [2]
}

Drag options to blanks, or click blank then click option'

Afalse

Btrue

Caws_route_table.private.id

Daws_route_table.public.id

Attempts:

3 left

💡 Hint

Common Mistakes

Setting map_public_ip_on_launch to true for private subnet

Associating private subnet with public route table

Private subnets do not assign public IPs automatically, so map_public_ip_on_launch is false. They are associated with the private route table.

5fill in blank

hard

Fill all three blanks to define a NAT gateway in a public subnet with an Elastic IP and associate it with the private route table.

AWS

resource "aws_eip" "nat_eip" {
  vpc = true
}

resource "aws_nat_gateway" "main" {
  allocation_id = aws_eip.nat_eip.id
  subnet_id     = [1]
}

resource "aws_route" "private_nat_route" {
  route_table_id         = [2]
  destination_cidr_block = "0.0.0.0/0"
  [3]              = aws_nat_gateway.main.id
}

Drag options to blanks, or click blank then click option'

Aaws_subnet.public.id

Baws_route_table.private.id

Cnat_gateway_id

Daws_subnet.private.id

Attempts:

3 left

💡 Hint

Common Mistakes

Placing NAT gateway in private subnet

Using public route table for private subnet route

Using gateway_id instead of nat_gateway_id for NAT gateway route

The NAT gateway must be in the public subnet (aws_subnet.public.id), the private route table is used for the route, and the route uses nat_gateway_id to point to the NAT gateway.