Explained

Assumptions

• Basic network knowledge (e.g. CIDR, Source and Destination NAT)
• Basic iptables knowledge
• Pod/Cluster CIDR: 100.64.0.0/13
  • Every node gets a /24 podCIDR.
• Service IP CIDR: 100.72.0.0/16
• Node IP CIDR: 10.10.10.0/24

More info on IP Classless Inter-Domain Routing (short CIDR):

• IPv4 Classless Inter-Domain Routing
• IPv6 Classless Inter-Domain Routing

The source for the diagrams, can be found as .graphml at the same path as the images.

Example: kubernetes-networking-explained-network_stack.svg -> kubernetes-networking-explained-network_stack.graphml

Network Stack

Traffic Flow

Pod to Pod

Pod to Service IP

Service IP iptables

NodePort to Service IP to Pod