Public S3 bucket access using s3.amazonaws.com/bucket/folder is possible but not using s3-us-east-1.amazonaws.com/bucket/folder

Question

I am trying to figure out why I can't access my public bucket's resources located in us-east-1 region using the following URL:

https://s3-us-east-1.amazonaws.com/demo.terraform.bucket/VideoImages/public.png

I get that error when I try to execute the above URL in the browser:

s3-us-east-1.amazonaws.com’s server IP address could not be found.

However, if I use the bellow URL it works and I get the resource:

https://s3.amazonaws.com/demo.terraform.bucket/VideoImages/public.png

I have another public bucket which was created by someone else in my team in a different region us-west-2 and I can access it using the https://s3-us-west-2.amazonaws.com/<bucketname>/VideoImages/public.png format.

I am trying to figure out what is going on with the access of my bucket demo.terraform.bucket . Why I can't access images using that syntacs https://s3-<region>.amazonaws.com/<bucket name>/VideoImages/public.png ?

Bucket policy:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "AllowPublicReadVideoImages",
            "Effect": "Allow",
            "Principal": {
                "AWS": "*"
            },
            "Action": "s3:GetObject",
            "Resource": "arn:aws:s3:::demo.terraform.bucket/VideoImages/*"
        },
        {
            "Sid": "AllowPublicReadMarketing",
            "Effect": "Allow",
            "Principal": {
                "AWS": "*"
            },
            "Action": "s3:GetObject",
            "Resource": "arn:aws:s3:::demo.terraform.bucket/MarketingResources/*"
        }
    ]
}

And I have Block all public access set to Off

Answer 1

s3-us-east-1.amazonaws.com returns NXDOMAIN for A/AAAA queries, ie it doesn't exist. Domains of the format s3-<region>.amazonaws.com are legacy and exist only for select regions with often non-standard names. You should no longer use them.

The modern format for S3 domains is s3.dualstack.<region>.amazonaws.com/<bucket> . Stick to that and don't forget the dualstack bit for IPv6 support.