Hi n3kerr,
NAS (network access server) provides network access for clients. A NAS using a RADIUS infrastructure is a RADIUS client. Client computers, such as wireless laptop computers and other computers running client operating systems, are not RADIUS clients.
In the event viewer, the entries of NAS records the information of the server that forward connection request to NPS, such as VPN connection, then the information is associated with VPN server.
The entry of calling station identifier records the IP address of the device's IP address, such as PC, and they are VPN clients, but not NPS clients.
Best regards,
Anne he