Update information about network sizes

docs/large-deployments.md

@@ -34,6 +34,9 @@ For a large scaled deployments, consider the following configuration changes:
   ``kube_controller_pod_eviction_timeout`` for better Kubernetes reliability.
   Check out [Kubernetes Reliability](kubernetes-reliability.md)
 
+* Tune network prefix sizes. Those are ``kube_network_node_prefix``,
+  ``kube_service_addresses`` and ``kube_pods_subnet``.
+
 * Add calico-rr nodes if you are deploying with Calico or Canal. Nodes recover
   from host/network interruption much quicker with calico-rr. Note that
   calico-rr role must be on a host without kube-master or kube-node role (but

roles/kubespray-defaults/defaults/main.yaml

@@ -99,7 +99,15 @@ kube_pods_subnet: 10.233.64.0/18
 
 # internal network node size allocation (optional). This is the size allocated
 # to each node on your network.  With these defaults you should have
-# room for 4096 nodes with 254 pods per node.
+# room for 64 nodes with 254 pods per node.
+# Example: Up to 256 nodes, 100 pods per node (/16 network):
+#  - kube_service_addresses: 10.233.0.0/17
+#  - kube_pods_subnet: 10.233.128.0/17
+#  - kube_network_node_prefix: 25
+# Example: Up to 4096 nodes, 100 pods per node (/12 network):
+#  - kube_service_addresses: 10.192.0.0/13
+#  - kube_pods_subnet: 10.200.0.0/13
+#  - kube_network_node_prefix: 25
 kube_network_node_prefix: 24
 
 # The virtual cluster IP, real host IPs and ports the API Server will be