Private link vs VPC peering

Question

I need to set up a connection between VPCs. My plan was VPC peering but customer asks for Private Link as they heard it is the secure way. But I am mostly concerned with performance overhead with the private link. What I understood (maybe wrong); in the Private Link architecture there is an extra NLB. Does not this introduce a latency because of extra network hop?

Answer 1

VPC peering and Private Link serve two different purposes .

VPC peering enables you to connect two VPC in a same way you would connect to local networks together, and remote networks using VPN. VPC peering allows network traffic from one VPC to the second VPC. For example, you can SSH from an instance in VPC A into an instance in VPC B.

Private Link is used to expose individual services of yours in VPC A to VPC B. But this does not allow for free flow of network traffic from VPC A to VPC B. For example, lets say you've developed very cool application for image segmentation. The application and all its databases and other resources that it requires are in VPC A. Now a friend comes and he/she would like to use your application. But the friend is in VPC B. Since your application is private, not exposed to the internet, a way for your friend to use the app would be to expose it through Private Link. For this you create NLB in-front of your application, and your friend will get network interface in his VPC B through which he can access your private application in VPC A.

Based on this and your question, there is no clear answer as the two options are used for different purposes. I would suggest to clarify exactly what are your or your customer requirements.

But generally, both will be equally fast. AWS docs write about VPC peering the following:

AWS uses the existing infrastructure of a VPC to create a VPC peering connection; it is neither a gateway nor a VPN connection, and does not rely on a separate piece of physical hardware. There is no single point of failure for communication or a bandwidth bottleneck .

Other examples from AWS docs is here:

• Example: Services Using AWS PrivateLink and VPC Peering

Edit: Based on @Michael comment.