Amazon CloudFront adds support for client IP address and connection port header

Amazon CloudFront now provides a CloudFront-Viewer-Address header that includes IP address and connection port information for requesting clients. The connection port field indicates the TCP source port used by the requesting client. Previously, IP address and client connection port information were available only in CloudFront access logs, making it harder to resolve issues or perform real-time decision-making based on these data. Now you can configure your CloudFront origin request policies to forward the CloudFront-Viewer-Address header to your origin servers. The header can also be used in CloudFront Functions when included in an origin request policy. The CloudFront-Viewer-Address header uses the following syntax: CloudFront-Viewer-Address: 127.0.0.1:4430

Source:: Amazon AWS