Enhance Amazon EKS network security posture with DNS and admin network policies

This article explains Amazon EKS's new DNS-based and Admin network policies for enhanced cluster security and external service access control.

• Admin network policies provide cluster-wide, cross-namespace security controls that cannot be overridden
• DNS-based policies use domain names instead of IP addresses for stable, maintainable external access rules
• EKS Auto (v1.29+) supports both policy types; EC2-based EKS supports Admin policies via VPC CNI v1.21.0+
• Use cases include blocking IMDS access, securing multi-tenant AWS service access, and hybrid cloud integration
• Implement deny-by-default baseline policies with label-based segmentation for scalable security
• Combine DNS policies with traditional network policies for defense-in-depth security architecture
• Admin Deny policies take precedence; Pass actions delegate to namespace-scoped policies
• Monitor policy logs and validate DNS policies in staging environments before production deployment

These policies simplify network security management by replacing IP-based rules with stable domain names while enabling centralized, cluster-wide security governance.