VPC in aws interview questions
Here are some common VPC (Virtual Private Cloud) related interview questions along with answers.
1. Question: What is a VPC in AWS?
Answer: A VPC (Virtual Private Cloud) is a virtual network environment within AWS that allows you to logically isolate and control the networking aspects of your cloud infrastructure. It enables you to create a private, isolated network environment in the cloud where you can deploy AWS resources such as EC2 instances, RDS databases, and Lambda functions.
2. Question: What are the components of a VPC?
Answer: The key components of a VPC include:
— Subnets: Segments of the VPC’s IP address range where you can place AWS resources.
— Route Tables: Define routing rules for traffic within the VPC and to external networks.
— Internet Gateways (IGW): Enable communication between the VPC and the internet for resources with public IP addresses.
— NAT Gateways/NAT Instances: Allow resources in private subnets to access the internet while remaining private.
— Elastic IP Addresses (EIPs): Static IP addresses that can be assigned to EC2 instances or NAT gateways for internet access.
— Security Groups: Act as virtual firewalls to control inbound and outbound traffic to AWS resources.
3. Question: How does VPC peering work?
Answer: VPC peering allows you to connect two VPCs to communicate with each other using private IP addresses as if they were part of the same network. Once a peering connection is established between two VPCs, instances in one VPC can communicate directly with instances in the other VPC using private IP addresses. VPC peering does not require a separate gateway or VPN connection and does not rely on internet access.
4. Question: What is the difference between a public subnet and a private subnet in a VPC?
Answer:
— Public Subnet: A subnet with a route to an Internet Gateway (IGW), allowing instances within the subnet to have public IP addresses and communicate directly with the internet.
— Private Subnet: A subnet without a route to an IGW, making instances within the subnet inaccessible from the internet. Instances in a private subnet can still access the internet through a NAT Gateway or NAT Instance in the public subnet.
5. Question: How do you secure a VPC?
Answer: To secure a VPC, you can implement various security measures such as:
— Properly configuring security groups and network access control lists (ACLs) to control inbound and outbound traffic.
— Using private subnets to restrict direct access to resources from the internet.
— Implementing encryption for data in transit and at rest using services like AWS Key Management Service (KMS) and SSL/TLS.
— Enforcing multi-factor authentication (MFA) and strong password policies for IAM users accessing the VPC.
— Regularly monitoring and auditing VPC activity using AWS CloudTrail and Amazon CloudWatch Logs to detect and respond to security incidents.
These questions cover fundamental concepts related to VPCs in AWS and provide a solid foundation for understanding networking in the cloud environment.
