text: OpenShift SDN maintains a registry of all nodes in the cluster. This registry is stored in etcd. 
  When the system administrator registers a node, OpenShift SDN allocates an unused /23 
  subnet from the cluster network and stores this subnet in the registry. When a node is 
  removed or deleted from the cluster, the OpenShift SDN frees the corresponding cluster 
  network subnet. This subnet becomes available for future allocations to new nodes. 
  
  This subnet value for nodes is specified in the Ansible inventory host variable 
  osm_cluster_network_cidr. The default network if this variable is not set is 10.128.0.0./14 
  (for example, 10.128.0.0 - 10.131.255.255). 
  
  The nodes are allocated /23 subnets (for example, 10.128.0.0/23, 10.128.2.0/23, 
  10.128.4.0/23, and others). Therefore, the cluster network has 512 subnets that are available 
  to assign to nodes, and a specific node is allocated 510 addresses that it can assign to the 
  containers that are running on it. 
  
  When the ovs-multitenant plug-in is used, the OpenShift SDN master also watches for the 
  creation and deletion of projects and assigns VXLAN VNIDs to them. These VXLAN VNIDs 
  are used later by the nodes to isolate traffic correctly. 