US Patent 11405378 Post-connection client certificate authentication

A network access control (NAC) device detects a connection of an endpoint device at a network switch coupled to a network and restricts access of the endpoint device to prevent the endpoint device from accessing resources of the network. The NAC device establishes a connection with the endpoint device, validates a client certificate corresponding to the endpoint device to authenticate the endpoint device as a corporate device and grants the endpoint device access to the resources of the network.