# Cluster 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**