VPC CNI ENI-to-Pod IP Mapping

VPC CNI ENI-to-Pod IP Mapping An architecture diagram generated by Archify. Primary ENI · eth0 · EC2 Instance (Worker Node) · hands out secondary IPs Primary ENI eth0 hands out secondary IPs Secondary ENI · eth1 · EC2 Instance (Worker Node) · hands out secondary IPs Secondary ENI eth1 hands out secondary IPs Secondary ENI · eth2 · spare (idle) · EC2 Instance (Worker Node) · spare capacity (idle) Secondary ENI eth2 · spare (idle) spare capacity (idle) Pod 1 · Secondary IP · EC2 Instance (Worker Node) › Pods Pod 1 Secondary IP Pod 2 · Secondary IP · EC2 Instance (Worker Node) › Pods Pod 2 Secondary IP Pod 3 · Secondary IP · EC2 Instance (Worker Node) › Pods Pod 3 Secondary IP Pod 4 · Secondary IP · EC2 Instance (Worker Node) › Pods Pod 4 Secondary IP EC2 Instance (Worker Node) Pods Legend Backend Cloud

How VPC CNI Works

  • • Each Pod receives a real VPC IP address (a secondary IP of an ENI)
  • • eth2 is held in reserve as spare capacity not yet assigned to any Pod
  • • Max ENIs and IPv4 addresses per ENI for the instance type determine the node's max Pods