Exam-style
An assistant on ECS in a private subnet calls Amazon Bedrock through a NAT gateway. Asked to take those calls off the public service endpoint, the team adds an interface VPC endpoint for the Bedrock runtime using AWS PrivateLink. The security lead then records two entries: model traffic is now encrypted, and access to Bedrock is now restricted. Which reading is right?
Reveal the answer
B. The encryption entry is wrong, since TLS already encrypted the call and the endpoint changed the route, not the ciphertext. The access entry holds only if an endpoint policy names which principals and which models may pass through
Three controls are being fused into one. AWS PrivateLink changes the network path: an interface endpoint puts a private IP address for the Bedrock APIs in the team’s own subnets, so the SDK call resolves there and needs no internet gateway or NAT device. The payload is untouched. Bedrock requires TLS 1.2 or better on every API call, so the request through the NAT gateway the day before was encrypted too. AWS KMS covers the at-rest half. The encryption entry records something the team already had. The endpoint policy is what arrives with the endpoint: a resource policy naming which principals may use it and which models they may reach, evaluated alongside the calling role’s IAM policy. Leave it off and the default allows full access. The endpoint governs only the traffic through it: the public Bedrock endpoint stays reachable by credentials used elsewhere, which IAM conditions handle.
Q. The team adds an interface VPC endpoint for Bedrock and records the traffic as encrypted and access as restricted. Which entry is wrong?
A. The encryption entry. AWS PrivateLink changes the route, not the ciphertext, and the access entry only holds up if an endpoint policy was attached.
Why? Keep three controls apart. AWS PrivateLink puts a private IP address for the Bedrock APIs in your own subnets, so the call reaches the service with no internet gateway or NAT device in the path. TLS encrypts the request in transit and was already doing so through the NAT gateway, since Bedrock requires TLS 1.2 or better on every API call. AWS KMS encrypts what gets stored, from custom models and agents to the documents and logs in S3. Those two together are encryption in transit and at rest. The endpoint’s own policy is the access-control gain, naming which principals and which models may be reached through it on top of the caller’s IAM policy. Two things worth carrying: an endpoint with no policy restricts nobody, and taking the NAT gateway out of this route ends its per-gigabyte data processing charge, though the endpoint has a per-gigabyte charge of its own.