I recently received a dialog box on my MacBook Air (10.9.2 Client) asking "Do you want the application “ntpd” to accept incoming network connections?". I have OS X's firewall enabled.
Now, my understanding is that ntpd on OS X Client is only for setting local machine time from a remote NTP server. It should not be acting as a time server for anyone else, so accepting (presumably new, not established) incoming connections should not be necessary.
I was wondering if my machine was being hit by a rogue machine on the network attempting (or a victim of) the NTP server packet amplification attacks that have been going on recently?