A company uses AWS Systems Manager Session Manager to manage EC2 instances in the eu-west-1...

The AWS Cloud Operations and Systems Manager documentation states that to use Session Manager privately within a VPC (without internet access), three interface VPC endpoints must be configured:

com.amazonaws.<region>.ssm – enables Systems Manager core API communication.

com.amazonaws.<region>.ec2messages – allows the agent to send and receive messages between EC2 and Systems Manager.

com.amazonaws.<region>.ssmmessages – enables real-time interactive communication for Session Manager connections.

These endpoints ensure secure, private connectivity over the AWS network, eliminating the need for public internet routing.

Endpoints for S3, Step Functions, or EC2 API (Options C, E, F) are not required for Session Manager functionality.

Thus, the correct combination is A, B, and D, aligning with AWS CloudOps best practices for secure, private Systems Manager access.