OS X Firewall - Time Service (NTP Port 123)

Discussion in 'macOS' started by mkrishnan, Mar 7, 2006.

  1. mkrishnan Moderator emeritus


    Jan 9, 2004
    Grand Rapids, MI, USA
    Quick question... there is an option in the OS X Firewall to open Port 123 for NTP (date and time service). Is this only necessary for making the Mac a NTP SERVER, or is it also necessary for the Mac to be a client? It seems like the former. I noticed my port was open, and from what I can tell, there's no reason for it to be, and it doesn't seem to open automatically when you enable NTP in the Date & Time prefs (i.e. it isn't open, but greyed out, like the Web Server port is, when you have Personal Web Sharing on -- in that case, you are not able to close the port unless you first turn off web sharing).

    Thanks! :)
  2. yellow Moderator emeritus


    Oct 21, 2003
    Portland, OR
    Only if you want your Mac to act as an NTP server.

    Otherwise it's not needed. All the outbound requests should not be blocked, and received answers from outbound requests should auto-magically be recognized.

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