Question #743
What is the primary role of an internet gateway in an Amazon VPC?
To establish a dedicated network connection to on-premises data centers
To facilitate bidirectional communication between the VPC and the internet
To monitor and restrict data transfer speeds to the internet
To distribute incoming internet traffic across multiple Availability Zones
Explanation
Answer B is correct because an internet gateway (IGW) allows instances in a VPC to communicate with the internet (outbound traffic) and enables the internet to initiate connections with instances (inbound traffic). It achieves this by performing network address translation (NAT) for public IPv4 addresses and serving as a target in VPC route tables for internet-bound traffic.
Option A is incorrect because dedicated connections to on-premises data centers are handled by AWS Direct Connect or VPNs, not an IGW. Option C is incorrect because IGWs do not monitor or restrict data transfer speeds; this is managed through other services like Amazon CloudWatch or security groups. Option D is incorrect because distributing traffic across Availability Zones is the role of load balancers (e.g., ALB, NLB), not an IGW.
Key Points:
- IGW enables bidirectional internet access for VPC resources.
- Requires proper route table configuration (0.0.0.0/0 → IGW).
- Public IPv4 addresses or Elastic IPs are required for instances to communicate via the IGW.
- IGW is horizontally scaled and highly available by default.
Answer
The correct answer is: B