Inbound and outbound rules in AWS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to allow inbound HTTP traffic on port 80.

AWS

SecurityGroupIngress:
  - IpProtocol: "tcp"
    FromPort: [1]
    ToPort: 80
    CidrIp: "0.0.0.0/0"

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

A80

B8080

C22

D443

Attempts:

3 left

💡 Hint

Common Mistakes

Using port 22 which is for SSH instead of HTTP.

Using port 443 which is for HTTPS.

Port 80 is the standard port for HTTP traffic, so it must be set as the FromPort to allow inbound HTTP.

2fill in blank

medium

Complete the code to allow outbound traffic to any IP on all ports.

AWS

SecurityGroupEgress:
  - IpProtocol: "-1"
    FromPort: 0
    ToPort: [1]
    CidrIp: "0.0.0.0/0"

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

A443

B22

C80

D65535

Attempts:

3 left

💡 Hint

Common Mistakes

Setting ToPort to 80 or 443 limits outbound traffic to only those ports.

Using port 22 which is for SSH and not all ports.

Port 65535 is the highest port number, so setting ToPort to 65535 allows all ports outbound.

3fill in blank

hard

Fix the error in the inbound rule to allow HTTPS traffic on port 443.

AWS

SecurityGroupIngress:
  - IpProtocol: "tcp"
    FromPort: [1]
    ToPort: [2]
    CidrIp: "0.0.0.0/0"

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

A22

B443

C8080

D80

Attempts:

3 left

💡 Hint

Common Mistakes

Leaving ToPort as 80 which is for HTTP.

Using port 22 which is for SSH.

HTTPS traffic uses port 443, so both FromPort and ToPort must be set to 443 to allow HTTPS inbound.

4fill in blank

hard

Fill both blanks to allow inbound SSH traffic only from a specific IP range.

AWS

SecurityGroupIngress:
  - IpProtocol: [1]
    FromPort: [2]
    ToPort: 22
    CidrIp: "203.0.113.0/24"

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

A"tcp"

B"udp"

C22

D80

Attempts:

3 left

💡 Hint

Common Mistakes

Using UDP protocol instead of TCP.

Setting FromPort to 80 which is for HTTP.

SSH uses TCP protocol on port 22, so IpProtocol must be "tcp" and FromPort must be 22.

5fill in blank

hard

Fill all three blanks to create an outbound rule allowing DNS queries over UDP port 53.

AWS

SecurityGroupEgress:
  - IpProtocol: [1]
    FromPort: [2]
    ToPort: [3]
    CidrIp: "0.0.0.0/0"

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

A"tcp"

B"udp"

C53

D22

Attempts:

3 left

💡 Hint

Common Mistakes

Using TCP protocol instead of UDP.

Setting ports to 22 which is for SSH.

DNS queries typically use UDP protocol on port 53, so IpProtocol is "udp" and both FromPort and ToPort are 53.

Practice

1. What do inbound rules in a security group control in AWS?

easy

A. Both incoming and outgoing traffic

B. Outgoing traffic from your resources

C. Incoming traffic to your resources

D. Traffic between AWS regions

Solution

1. Step 1: Understand inbound rules purpose

   Inbound rules specify what incoming network traffic is allowed to reach your AWS resources.

2. Step 2: Differentiate inbound from outbound

   Outbound rules control outgoing traffic, so inbound rules only affect incoming connections.

3. Final Answer:

   Incoming traffic to your resources -> Option C

4. Quick Check:

   Inbound = Incoming traffic [OK]

Hint: Inbound means incoming traffic allowed [OK]

Common Mistakes:

• Confusing inbound with outbound rules
• Thinking inbound controls outgoing traffic
• Assuming inbound controls both directions

2. Which of the following is the correct way to allow HTTP traffic inbound on port 80 in an AWS security group?

easy

A. Allow TCP traffic on port 80 inbound

B. Allow TCP traffic on port 22 inbound

C. Allow UDP traffic on port 80 outbound

D. Allow ICMP traffic inbound

Solution

1. Step 1: Identify HTTP port and protocol

   HTTP uses TCP protocol on port 80.

2. Step 2: Match rule to allow inbound HTTP

   Allowing TCP traffic on port 80 inbound correctly permits HTTP requests.

3. Final Answer:

   Allow TCP traffic on port 80 inbound -> Option A

4. Quick Check:

   HTTP = TCP port 80 inbound [OK]

Hint: HTTP uses TCP port 80 inbound [OK]

Common Mistakes:

• Using wrong port number for HTTP
• Allowing outbound instead of inbound
• Using UDP instead of TCP for HTTP

3. Given this security group outbound rule: Allow all traffic (all protocols) to 0.0.0.0/0, what is the effect?

medium

A. Allows outbound traffic only on port 443

B. Blocks all outbound traffic

C. Allows inbound traffic from any IP

D. Allows all outbound traffic to any IP

Solution

1. Step 1: Analyze the outbound rule details

   The rule allows all protocols and all ports outbound to any IP address (0.0.0.0/0 means anywhere).

2. Step 2: Understand outbound traffic effect

   This means any outbound traffic from the resource is allowed to any destination.

3. Final Answer:

   Allows all outbound traffic to any IP -> Option D

4. Quick Check:

   Outbound all traffic to 0.0.0.0/0 = Allow all outbound [OK]

Hint: 0.0.0.0/0 means anywhere, all protocols means all traffic [OK]

Common Mistakes:

• Confusing inbound and outbound rules
• Thinking it blocks traffic
• Assuming it restricts ports

4. You created an inbound rule allowing TCP port 22 from 0.0.0.0/0 but cannot SSH into your EC2 instance. What is a likely cause?

medium

A. Security group is not attached to the instance

B. Inbound rule uses UDP instead of TCP

C. Port 22 is closed on the instance's OS firewall

D. Outbound rules block all traffic

Solution

1. Step 1: Check security group attachment

   Even if rules are correct, if the security group is not attached to the instance, rules won't apply.

2. Step 2: Consider other causes

   Outbound rules usually allow return traffic by default; OS firewall or protocol mismatch would cause different symptoms.

3. Final Answer:

   Security group is not attached to the instance -> Option A

4. Quick Check:

   Security group must be attached to instance [OK]

Hint: Check if security group is attached to instance [OK]

Common Mistakes:

• Ignoring security group attachment
• Assuming outbound rules block SSH
• Not checking OS firewall settings

5. You want to allow your web server to receive HTTP requests from anywhere but restrict outbound traffic to only HTTPS (port 443). Which inbound and outbound rules should you configure?

hard

A. Inbound: Allow UDP port 80 from 0.0.0.0/0; Outbound: Allow TCP port 443 to 0.0.0.0/0

B. Inbound: Allow TCP port 80 from 0.0.0.0/0; Outbound: Allow TCP port 443 to 0.0.0.0/0

C. Inbound: Allow TCP port 443 from 0.0.0.0/0; Outbound: Allow TCP port 80 to 0.0.0.0/0

D. Inbound: Allow TCP port 80 from 192.168.0.0/24; Outbound: Allow all traffic to 0.0.0.0/0

Solution

1. Step 1: Set inbound rule for HTTP

   Allow TCP port 80 inbound from anywhere (0.0.0.0/0) to receive HTTP requests.

2. Step 2: Set outbound rule for HTTPS only

   Allow TCP port 443 outbound to anywhere to restrict outgoing traffic to HTTPS.

3. Final Answer:

   Inbound: Allow TCP port 80 from 0.0.0.0/0; Outbound: Allow TCP port 443 to 0.0.0.0/0 -> Option B

4. Quick Check:

   Inbound HTTP, outbound HTTPS only [OK]

Hint: Inbound HTTP port 80, outbound HTTPS port 443 [OK]

Common Mistakes:

• Mixing up inbound and outbound ports
• Using UDP instead of TCP for HTTP
• Restricting inbound to private IPs only