I have setup AWS Direct Connect for my AWS environment. I setup a public interface for S3 traffic, across DX link. I want other Internet traffic to use the existing link to an Internet Service Provider.
How do I configure AWS Direct Connect for access to S3? Do I need a static route that points to S3 then advertise a default route to AWS using BGP OR Redistribute BGP routes into the existing routing infrastructure, advertise specific routes for network to AWS?
If you have public direct connect with a public IP you will have access to all public AWS endpoints via that connection. AWS will advertise all public prefixes they own in that region (or all of north america if your connection is in North america) back to you to ensure you have a route to these endpoints, so you will not need a static route.
If you look here AWS Direct Connect FAQS the question "Q: What are the technical requirements for virtual interfaces to public AWS services such as Amazon EC2 and Amazon S3?" will explain a little more about how this works.