How can we block AirDrop or AFP on a LAN?

Question

We have a wireless network that is open to students (which requires their School ID/Password) and when on it users can openly see other users home folders. Obviously students have turned on filesharing on their own for at home or elsewhere and forgot. We are now sending emails to those students that have their laptops wide open to others but from a security stand point the college would like to block AirDrop & AFP on the LAN. The open wireless is just for internet access and not to connect to other devices, shares etc.
Thank you,
Carter

Answer 1

TCP port 548 is needed for AFP file sharing, blocking this port should get the job done. Keep in mind that AirDrop is available to them regardless, even if they are not connected to the student network. AirDrop is capable of creating a direct connection with another Mac using it's AirPort card so managing/controlling that will be very difficult.
Education is more work but will be more useful for the students in the long run. It's far more valuable for them to know what kind of issues/risks they may be opening their Macs up to rather than just blocking AFP. Even if AFP is blocked, continuing with those emails or some other form of awareness/education on the subject is recommended.