Cluster Networking

Kubernetes Networking

Kubernetes networking consists of several key components that enable seamless communication between pods, services, and external clients.

Pod-to-Pod Communication

• Kubernetes assigns each pod a unique IP from the containerCIDR.
• Pods within the same node communicate via the local bridge network.
• Inter-node pod communication is enabled through an overlay network (VXLAN, IP-in-IP) or direct routing.

Service Networking

• Services expose workloads internally using a virtual IP assigned from the servicesCIDR.
• kube-proxy manages traffic routing using iptables generally.
• External access is provided via LoadBalancer (cloud provider integration), NodePort, or Ingress.

ContainerCIDR and ServicesCIDR

• Container CIDR defines the range of IPs allocated to pods.

  • The default pod CIDR for PCD Kubernetes cluster is 10.244.0.0/16
  • Must not overlap with PCD Virtualization private networks.

• Service CIDR defines the range of virtual IPs assigned to services.

  • The default service CIDR for PCD Kubernetes cluster is 10.96.0.0/16