AWS - Security Groups and Network ACLs
You have two EC2 instances in the same VPC. Instance A's security group allows inbound SSH from Instance B's security group. What must be true for Instance B to SSH into Instance A?
You have two EC2 instances in the same VPC. Instance A's security group allows inbound SSH from Instance B's security group. What must be true for Instance B to SSH into Instance A?
hard📝 Application Q9 of 15
Step-by-Step Solution
Solution:
Step 1: Understand security group referencing
Inbound rules can specify another security group as source to allow traffic from its instances.Step 2: Confirm requirement for SSH
Instance A must allow inbound SSH from Instance B's security group to accept connections.Final Answer:
Instance B's security group must be source in Instance A's inbound rule -> Option BQuick Check:
Security group source referencing = Instance B's security group must be specified as the source in Instance A's inbound rule [OK]
Quick Trick: Use security group ID as source to allow instance-to-instance traffic [OK]
Common Mistakes:
MISTAKES- Thinking public IP is required for private VPC communication
- Confusing outbound rules on Instance A
- Assuming internet gateway is needed for internal traffic
Master "Security Groups and Network ACLs" in AWS
Want More Practice?
15+ quiz questions · All difficulty levels · Free
Free Signup - Practice All QuestionsMore AWS Quizzes