This quiz is part of the DevOpsTheHardWay course.

Comprehension Check

Question 1

You deploy Flask webserver on an EC2 instance. Deploying the service in multiple subnets can ensure highly available and fault-tolerant architecture.

• True.
• False.
• True, only in case the subnets was created in different AZs.
• False, multiple VPCs can ensure highly available and fault-tolerant architecture.

Question 2

You are designing a VPC network for your AWS environment. You have created two subnets, Subnet A and Subnet B in the same AZ. Subnet A uses a CIDR block of 10.0.0.0/24, while Subnet B uses a CIDR block of 10.0.1.0/24.

What could be misconfiguration for the subnets CIDR?

• The CIDR blocks of Subnet A and Subnet B should overlap.
• The CIDR block of Subnet A should be smaller than the CIDR block of Subnet B.
• The CIDR block of Subnet A should be larger than the CIDR block of Subnet B.
• The CIDR blocks of Subnet A and Subnet B should have the same size.
• The configuration is good.

Question 3

Which one of the below statements corresponding to a public subnet:

• Public subnet includes a route in its associated routing table that routes traffic to a NAT gateway.
• Public subnet includes a route in its associated routing table that routes traffic to an internet gateway.
• Public subnet has a security group allowed inbound traffic from 0.0.0.0/0.
• None of the above.

Question 4

In your VPC, you have a route table with these routes:

1. Destination: 10.0.0.0/16, Target: Local
2. Destination: 0.0.0.0/0, Target: Internet Gateway
3. Destination: 10.0.1.0/24, Target: Virtual Private Gateway
4. Destination: 10.0.2.0/24, Target: NAT Gateway

If you have network traffic going to the IP address 10.0.0.10, which route will be used?

• 1
• 2
• 3
• 4

Question 5

You have two instances in your VPC:

1. Instance A is in Subnet A (10.0.1.0/24).
2. Instance B is in Subnet B (10.0.2.0/24).

Their security groups are set up like this:

Instance A's security group:

1. Allows all traffic from itself.
2. Allows SSH (port 22) from anywhere.

Instance B's security group:

1. Allows all traffic from itself.
2. Allows HTTP (port 80) from instance A's security group.

Despite this, instance A can't connect to instance B on port 80. What might be causing this problem?

• The security group of Instance B does not allow outbound traffic.
• The security group of Instance A does not allow outbound traffic.
• The CIDR blocks of Subnet A and Subnet B are overlapping.
• The security groups of both instances do not allow inbound traffic.
• None of the above

Question 6

Choose the possible potential problem(s) that cause stable communication issues between two instances located in different subnets on the same vpc:

• The security group attached to instance B does not allow outbound traffic at all
• The network interface instance A has does not allow socket connection
• Network throughput exceeded the maximum limit
• The Network ACL on subnet B does not allow outbound traffic
• The routing table of subnet A has no target to route to subnet B