Netgate Discussion Forum
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Search
    • Register
    • Login

    NTP Config Question

    Scheduled Pinned Locked Moved General pfSense Questions
    42 Posts 4 Posters 7.3k Views
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • stephenw10S
      stephenw10 Netgate Administrator
      last edited by

      You can just disable it for 10.10.10.1.

      Set outbound NAT to hybrid mode.

      Add a new rule. WAN. Check 'do not nat'. Source: 10.10.10.1.

      Steve

      1 Reply Last reply Reply Quote 0
      • J
        jchud
        last edited by

        Thanks. I disabled NAT for it and set up a floating ACL to block it from making an outboud connection. Which appears to have worked as I no longer see the occasional entry for it in the state table and its showing stuff in the states column on the firewall rule page. However it is not showing any entries of the rule being triggered in the firewall log page, is that normal? Also, not a result of this, but I occasionally see entries in the NTP log page that say something like some IP address local addr 10.10.10.1 -> <null> any idea what this is about?

        Lastly so I guess there is currently no way to get NTP to not listen/use IPv6?

        1 Reply Last reply Reply Quote 0
        • johnpozJ
          johnpoz LAYER 8 Global Moderator
          last edited by

          @jchud said in NTP Config Question:

          Lastly so I guess there is currently no way to get NTP to not listen/use IPv6?

          If you have IPv6 connectivity, and you just use fqdn for your ntp, and they get back AAAA then yeah they would connect via ipv6.

          But you sure can prevent clients on your end from using ipv6 to talk to your ntp server.. And if you don't want stuff to use ipv6.. Why do you have it enabled in the first place?

          An intelligent man is sometimes forced to be drunk to spend time with his fools
          If you get confused: Listen to the Music Play
          Please don't Chat/PM me for help, unless mod related
          SG-4860 24.11 | Lab VMs 2.8, 24.11

          J JKnottJ 2 Replies Last reply Reply Quote 0
          • stephenw10S
            stephenw10 Netgate Administrator
            last edited by

            Can we see that actual NTP log line?

            You won't see that traffic blocked in the firewall log unless you enabled logging in the floating rule.

            If IPs exist ntpd will listen on them including IPv6.

            Steve

            J 1 Reply Last reply Reply Quote 0
            • J
              jchud @johnpoz
              last edited by

              @johnpoz I have all IPv6 traffic blocked by the firewall plus do not have a gateway configured for it, nor a DHCP server configured to hand address for it, my wireless access point has as much disabled about it as I can, and all my LAN devices that I could I disabled it as well. If there is more I can do on the pfSense box that I can do to turn it off let me know. But for the time being when I look at the open sockets on pfSense it list ntpd as listening on like the IPv6 loopback address.

              johnpozJ 1 Reply Last reply Reply Quote 0
              • J
                jchud @stephenw10
                last edited by

                @stephenw10 I will post a copy of that line from the log file later, as I currently do not have access to it. In the meantime how do I enable logging in the floating rule, because all I saw was to "log the packet that triggered rule" and I don't specifically need to keep a copy of the packet itself? And I guess then that since I can't exactly disable pfSense from creating link local IPv6 addresses there is no way to stop ntpd from using them, would be nice though if there was like a flag that could be added to the config file or as part of the command that launches ntpd which specifies a specific version for it use.

                1 Reply Last reply Reply Quote 0
                • stephenw10S
                  stephenw10 Netgate Administrator
                  last edited by

                  That option just enables logging on the firewall rule. You will see traffic blocked by that rule in the firewall log. It doesn't store packets in any way.

                  Steve

                  J 1 Reply Last reply Reply Quote 0
                  • J
                    jchud @stephenw10
                    last edited by

                    @stephenw10 Oh ok my bad I thought checking that box would log the packet itself and thus the setting to have it log when the rule is triggered was somewhere else.

                    1 Reply Last reply Reply Quote 0
                    • johnpozJ
                      johnpoz LAYER 8 Global Moderator @jchud
                      last edited by

                      @jchud said in NTP Config Question:

                      it list ntpd as listening on like the IPv6 loopback address.

                      Yeah so.. even if you disabled ipv6 the loopback would still be there. Its almost impossible to git rid of the loopback ipv6 address "::1" as this is linked into the OS at very low level.

                      If your not creating a ip6 enabled on your lan, and don't have RA running there is no way clients to get an IPb6 address. Sure they could still have loopback, and even a link local maybe depending how you disabled ipv6 exactly.. But client not going to be able to use ipv6 to talk to your ntp server.

                      An intelligent man is sometimes forced to be drunk to spend time with his fools
                      If you get confused: Listen to the Music Play
                      Please don't Chat/PM me for help, unless mod related
                      SG-4860 24.11 | Lab VMs 2.8, 24.11

                      J 1 Reply Last reply Reply Quote 0
                      • J
                        jchud @johnpoz
                        last edited by

                        @johnpoz Yeah kind of what I figured, was just hoping there was some kind of way to tell ntpd to ignore using it anyway.

                        johnpozJ 1 Reply Last reply Reply Quote 0
                        • stephenw10S
                          stephenw10 Netgate Administrator
                          last edited by

                          I could see it being rejected because all services on the firewall are limited by the firewall rules rather where they listen but you could open a feature request for it:
                          https://redmine.pfsense.org

                          Steve

                          1 Reply Last reply Reply Quote 0
                          • johnpozJ
                            johnpoz LAYER 8 Global Moderator @jchud
                            last edited by johnpoz

                            @jchud said in NTP Config Question:

                            was just hoping there was some kind of way to tell ntpd to ignore using it anyway.

                            Why? Not understanding the point..

                            I just looked at the ntp conf created when you only list specific interfaces to list, and it is placing the ignore all and wildcard statements in the ntpd.conf

                            But still lists listening on ::1, but not sure why it matters? Not like something can talk to that.

                            An intelligent man is sometimes forced to be drunk to spend time with his fools
                            If you get confused: Listen to the Music Play
                            Please don't Chat/PM me for help, unless mod related
                            SG-4860 24.11 | Lab VMs 2.8, 24.11

                            J 1 Reply Last reply Reply Quote 0
                            • J
                              jchud @johnpoz
                              last edited by

                              @johnpoz More of a if its not needed/being used why have it even running as such anyway type ideology.

                              1 Reply Last reply Reply Quote 0
                              • johnpozJ
                                johnpoz LAYER 8 Global Moderator
                                last edited by johnpoz

                                I hear you - but ::1, has been been tied into the os at such a level.. I don't see how you could stop it. Like I said even when you disable ipv6 your still going to see that there.

                                They might be able to change ntp to be bound to IP vs the interface to remove that... But then your going to run into issues if user changes the interface IP for some reason that ntp is suppose to be listening on.

                                if you look at the conf being created you can see how they tell ntp to ignore all and wildcard, and then just calls out the interfaces you have highlighted to listen on in the gui

                                interface ignore all
                                interface ignore wildcard
                                interface listen igb3
                                interface listen igb0
                                interface listen igb2
                                interface listen igb2.4
                                interface listen igb5
                                

                                An intelligent man is sometimes forced to be drunk to spend time with his fools
                                If you get confused: Listen to the Music Play
                                Please don't Chat/PM me for help, unless mod related
                                SG-4860 24.11 | Lab VMs 2.8, 24.11

                                J 1 Reply Last reply Reply Quote 0
                                • J
                                  jchud @johnpoz
                                  last edited by

                                  @johnpoz Yeah complete aware of all that. Was just kind of hoping there was something like adding a -v4 flag to the ntpd command or in the conf file (though I guess in the case it would be more like "interface ignore IPv6") type deal. Not to mention any time I make a manual change to the conf file it just gets rolled back to whatever is set via the GUI following a restart of service or pfSense.

                                  1 Reply Last reply Reply Quote 0
                                  • johnpozJ
                                    johnpoz LAYER 8 Global Moderator
                                    last edited by

                                    yeah you would have to change system.inc file

                                    An intelligent man is sometimes forced to be drunk to spend time with his fools
                                    If you get confused: Listen to the Music Play
                                    Please don't Chat/PM me for help, unless mod related
                                    SG-4860 24.11 | Lab VMs 2.8, 24.11

                                    1 Reply Last reply Reply Quote 0
                                    • JKnottJ
                                      JKnott @johnpoz
                                      last edited by

                                      @johnpoz said in NTP Config Question:

                                      If you have IPv6 connectivity, and you just use fqdn for your ntp, and they get back AAAA then yeah they would connect via ipv6.
                                      But you sure can prevent clients on your end from using ipv6 to talk to your ntp server.. And if you don't want stuff to use ipv6.. Why do you have it enabled in the first place?

                                      Wouldn't it be easier to configure DNS to provide only an IPv4 address? If there are no AAAA records from the DNS, then the client can't use them. In my DNS I have to specify both IPv4 and IPv6 addresses for each host name.

                                      PfSense running on Qotom mini PC
                                      i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
                                      UniFi AC-Lite access point

                                      I haven't lost my mind. It's around here...somewhere...

                                      1 Reply Last reply Reply Quote 0
                                      • johnpozJ
                                        johnpoz LAYER 8 Global Moderator
                                        last edited by johnpoz

                                        Exactly if dns does not return AAAA then client would never try and access IPv6 because it wouldn't know where to go..

                                        I think the OP is more concerned that ntp is showing to be listening on ::1, vs any sort of actual issue.

                                        On linux you could prob do something like ntpd_opts with -4 -g or the like, but I don't think that works with freebsd..

                                        An intelligent man is sometimes forced to be drunk to spend time with his fools
                                        If you get confused: Listen to the Music Play
                                        Please don't Chat/PM me for help, unless mod related
                                        SG-4860 24.11 | Lab VMs 2.8, 24.11

                                        JKnottJ 1 Reply Last reply Reply Quote 0
                                        • JKnottJ
                                          JKnott @johnpoz
                                          last edited by

                                          @johnpoz said in NTP Config Question:

                                          I think the OP is more concerned that ntp is showing to be listening on ::1

                                          I'm trying to imagine how that would be a problem. Not having much luck.

                                          PfSense running on Qotom mini PC
                                          i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
                                          UniFi AC-Lite access point

                                          I haven't lost my mind. It's around here...somewhere...

                                          1 Reply Last reply Reply Quote 0
                                          • johnpozJ
                                            johnpoz LAYER 8 Global Moderator
                                            last edited by

                                            hehe on that we can agree ;)

                                            An intelligent man is sometimes forced to be drunk to spend time with his fools
                                            If you get confused: Listen to the Music Play
                                            Please don't Chat/PM me for help, unless mod related
                                            SG-4860 24.11 | Lab VMs 2.8, 24.11

                                            1 Reply Last reply Reply Quote 0
                                            • First post
                                              Last post
                                            Copyright 2025 Rubicon Communications LLC (Netgate). All rights reserved.