I have a single Windows 2008 R2 Standard server running NPS configured in my environment. The NPS server has 4 clients configured ( 4 wireless controllers). Everything is working well, no issues there.
However, for some odd reason; everyday at about the same time, the server will log 8 consecutive errors each for 2 different IP addresses in the event log.
Event ID 13 : A RADIUS message was received from the invalid RADIUS client IP address X.X.X.X
This error is always logged with the same 2 IP addresses. 8 errors for each IP. The IP's belong to a fileserver and an XP workstation running a print server.
Neither of these have anything to do with the RADIUS server, they are not clients and I cannot think of any reason they would be trying to contact it.
Any ideas what could be causing these messages from these seemingly 2 random IP's?