The Node Manager is responsible for creating and maintaining the node table for the controller. Each end-host (called a node) is uniquely identified by the combination of IP address and network segment. The data stored for each node includes the node’s MAC address, network interface, timeout value, and current location.
The Node Manager removes an entry from the table when the entry exceeds its timeout value. This behavior helps to ensure the table maintains an accurate representation of the live nodes on the controlled network.