Hey, I keep getting notices of a Vulnerability that has been blocked called a "Portscan".
I go to a college called Kent state and i use wifi provided on campus. The notification says:
Vulernability BLOCKED
When: Nov 29, 2011 9:41:15 PM
From ip-131-123-84-162.housing.res.kent.edu
Attack Name: Portscan
Application: /mach_kernel
I have NO idea what any of this means, but im afraid! The notifications keep popping up every 5-6 minutes. 
I just keep getting these little alerts, and I wanted to know what they were, if they were harmful and how to get rid of them.
Thanks.