Secure EC2 to S3 Communication
Question
You are responsible for several EC2 instances deployed from Amazon AMIs that are required to upload information to an S3 bucket.
This information must not traverse the public internet.
You must also be able to update the instances.
Which option is your best solution?
Answers
Explanations
Click on the arrows to vote for the correct answer
A. B. C. D.Answer - D.
Option A is incorrect.
VPN is not a solution for this case.
Option B and C are incorrect - Because both NAT gateway and NAT instance are used for private instances to communicate with the internet.
Option D is correct.
Tha main requirement of the question is that we need to upload information to S3 with out using internet.
S3 is a service residing outside the VPC.
We also need to update the server with the latest patches.
NAT Gateway is not required since AWS hosts YUM repository on S3can be accessed using S3 VPC GATEWAY endpoint, and doesn't need to go across the internet to get the server updates.
We need to create an S3 end point for the VPC and select the route table.
Subnets associated with selected route tables will be able to access this endpoint.
When we use an S3 end point to connect we will be using Amazon's internal network to communicate with the S3 rather than internet.
The best solution for uploading information from EC2 instances to S3 bucket without traversing the public internet while also allowing updates to the instances would be to use an S3 endpoint along with a NAT gateway (Option B).
Explanation:
An S3 endpoint is a logical entity within a VPC that enables direct access to S3 from within the VPC without having to traverse the public internet. With an S3 endpoint, traffic between the VPC and S3 is kept within the Amazon network.
However, to enable access to S3 from within a VPC, you also need to ensure that the S3 endpoint is configured correctly to route traffic to S3. In this case, since the requirement is to upload information to S3 and allow updates to the instances, using an S3 endpoint associated with a NAT gateway would be the best option.
A NAT (Network Address Translation) gateway is a highly available AWS managed service that enables instances within a private subnet to connect to the internet or other AWS services while also blocking inbound traffic. Using a NAT gateway would ensure that instances within a private subnet can communicate with S3 via the S3 endpoint while also preventing any inbound traffic.
Option A, which suggests using a VPN with IP addresses specified in the AWS official S3 prefix list, is not the best solution as it involves setting up and maintaining a VPN connection which can be complex and costly.
Option C suggests using a NAT instance, which is not as highly available as a NAT gateway, and requires more management and maintenance effort.
Option D suggests using an S3 endpoint associated with a VP (virtual private network), but this is not a valid option as there is no such thing as an S3 endpoint associated with a VP.
