Documentation: expand on CNI CIDRs in the kubeadm tutorial
@@ -5,10 +5,16 @@ It also assumes you've set up your system to use kubeadm. If you haven't done so
## Configuring CNI
-You'll need to use your plugins to figure out your pod-network-cidr. If you use the default bridge plugin defined [here](/contrib/cni/10-crio-bridge.conf), set
-```CIDR=10.85.0.0/16```
-If you're using a flannel network, set
-```CIDR=10.244.0.0/16```
+kubeadm expects a POD Network CIDR (`--pod-network-cidr`) to be defined when you install the cluster. The value of `--pod-network-cidr` depends on which CNI plugin you choose.
+
+| CNI Plugin | CIDR | Notes |
+| ----------------------- | ------------- | -------------- |
+| Bridge plugin (default) | 10.85.0.0/16 | The default bridge plugin is defined [here](/contrib/cni/10-crio-bridge.conf). This is only suitable when your cluster has a **single node**. |
+| Flannel | 10.224.0.0/16 | This is a good choice for clusters with multiple nodes. |
+
+For example, to use the script below with the **bridge** plugin, run `export CIDR=10.85.0.0/16`.
+
+A list of CNI plugins can be found in the [Cluster Networking](https://kubernetes.io/docs/concepts/cluster-administration/networking/) kubernetes documentation. Each plugin will define it's own default CIDR.
## Configuring Kubelet
