EKS Network Traffic Flow

EKS Network Traffic Flow An architecture diagram generated by Archify. Internet / kubectl · Operators · clients · Architecture component Internet / kubectl Operators · clients Control Plane · API server · scheduler · controllers · EKS cluster Control Plane API server · scheduler · controllers ClusterIP Service · In-cluster virtual IP · EKS cluster ClusterIP Service In-cluster virtual IP External Clients · User traffic · Architecture component External Clients User traffic LoadBalancer Service · NLB / ALB · EKS cluster LoadBalancer Service NLB / ALB Node 1 · kubelet · pods 1, 2 · EKS cluster Node 1 kubelet · pods 1, 2 Node 2 · kubelet · pods 3, 4 · EKS cluster Node 2 kubelet · pods 3, 4 kubectl API calls (443) kubelet traffic (10250) Cross-node pod traffic Internal traffic External traffic NodePort / target group EKS cluster Legend Backend Cloud Message bus External

Traffic types

  • • External API calls: kubectl and CI reach the API server on port 443
  • • Control-plane traffic: the API server talks to each node's kubelet on 10250
  • • Pod-to-pod traffic: the VPC CNI gives each pod a VPC IP, so pods talk directly without NAT

Service traffic

  • • ClusterIP is a virtual IP reachable only inside the cluster
  • • NodePort opens ports 30000-32767 on every node
  • • LoadBalancer provisions an NLB/ALB that forwards external traffic to pods