CIDR represents an IP address range with prefix notation. Anthos GKE planning applies CIDR blocks to separate node, Pod, and Service address pools; overlapping addresses are not permitted, and each cluster requires unique subnets. section 10.2.2
Size each address pool according to its operational responsibility:
- Node IPs cover GCE instances or nodes; estimate regional capacity from the number of clusters and maximum nodes per cluster. section 10.2.2
- Pod IP CIDR covers Pods; size it from maximum Pods per node and total nodes across the region. section 10.2.2
- Service IP CIDR provides one address for each ClusterIP Service. section 10.2.2
Sizing a Pod CIDR
For 110 Pods per node and 5,000 regional nodes, use 13 host bits for nodes and 8 for Pods, producing a Pod IP CIDR netmask of /11. section 10.2.2
