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    NTP Config Question

    Scheduled Pinned Locked Moved General pfSense Questions
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    • J
      jchud
      last edited by

      Sure, but what I think is happening is that it is occurring on the WAN interface so the firewall rules are seeing as it is coming from my public IP address while its actually the 10.10.10.1 address that is making the call. And I can see this in the state table as it list the VIP as the original source. So seeing as I can't just have a blanket outbound rule on my WAN blocking anything to port 123 I am not sure how to configure the rule in a way that only gets triggered when its VIP address making the request. Any suggestions would be greatly appreciated.

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      • stephenw10S
        stephenw10 Netgate Administrator
        last edited by

        You could just disable outbound NAT that IP and won't be able to make any outbound connections. You could block it as well then to be double sure.

        Steve

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        • J
          jchud
          last edited by

          But if I just flat out disable Outbound NAT how do I make so the other stuff on my network can get out, as I assume just like the VIP is doing any device on my network that is making such a connection is ultimately getting NATted as well.

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          • 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

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            • 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?

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              • 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.

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                    • 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.

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                      • 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.

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                          • 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

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                                • 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.

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                                    • 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.

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                                        • 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

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                                          • 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...

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