Monitoring of a life cycle of a connection of a network client device to a network via monitoring time synchronization traffic flowing between one or more network client devices and a time server in a network is provided. A system for monitoring a life cycle of a connection of a network client device to a network includes a security device operable to identify a true identity of the one or more network client devices, identify a network client device's connections to and disconnections from the network, determine which network client devices have been associated with a particular internet protocol (IP) address, and generate an output of connection and disconnection information associated with a network client device. In some examples, the security device is operable to detect anomalies and malicious patterns in the network.