Workload Cluster Network CIDR Ranges (Flannel Overlay)
Review the example CIDR ranges used for OKE network resources on Compute Cloud@Customer.
Throughout this documentation, variables are used to represent CIDR ranges for instances in different subnets. The following table lists the CIDR variables and example values for use with Flannel Overlay networking.
These are examples only. The CIDR ranges you use depend on the number of clusters you have, the number of nodes in each cluster, and the type of networking you are using.
For Flannel Overlay networking, IP addresses are managed by the underlying Container service. Pods are not assigned IP addresses from the IP address pool that is defined in the pod subnet CIDR. This is the reason you do not need a pod subnet when you are using Flannel Overlay networking.
The primary difference between IP address requirements of Flannel Overlay networking and VCN-Native Pod Networking is that VCN-Native Pod Networking requires more IP addresses to be available. The table in Workload Cluster Network CIDR Ranges (VCN-Native Pod) shows larger CIDR ranges than the following table for Flannel Overlay CIDR ranges. The CIDR ranges used with Flannel Overlay networking can be much smaller than the CIDR ranges used with VCN-Native Pod Networking.
|
Variable Name |
Description |
Example Value |
|---|---|---|
|
|
VCN CIDR range |
172.31.252.0/23 |
|
|
Worker subnet CIDR |
172.31.253.0/24 |
|
|
Worker load balancer subnet CIDR |
172.31.252.0/25 |
|
|
OKE control plane subnet CIDR |
172.31.252.224/28 |
|
|
OKE control plane load balancer subnet CIDR |
172.31.252.240/28 |
|
|
CIDR for clients that are allowed to contact the Kubernetes API server |
10.0.0.0/8 |
The IP Subnet Calculator on Calculator.net is one tool for finding all available networks for a given IP address and prefix length.
What's Next:
Review the network ports used for Flannel Overlay networking. See Workload Cluster Network Ports (Flannel Overlay).