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    Understanding how to get hostnames in IPv6 leases

    Scheduled Pinned Locked Moved DHCP and DNS
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    • kiokomanK
      kiokoman LAYER 8
      last edited by

      he's a bully
      he wants to impose his ideas instead of allowing the user to choose
      it is a shame that he is an Italian engineer to be NOT proud of

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      • G
        Gooberpatrol66 @JKnott
        last edited by

        @JKnott SLAAC means IPv6 addresses won't appear in the leases page, right?

        JKnottJ 1 Reply Last reply Reply Quote 0
        • kiokomanK
          kiokoman LAYER 8
          last edited by

          right, there are no lease state associated with SLAAC users.

          ̿' ̿'\̵͇̿̿\з=(◕_◕)=ε/̵͇̿̿/'̿'̿ ̿
          Please do not use chat/PM to ask for help
          we must focus on silencing this @guest character. we must make up lies and alter the copyrights !
          Don't forget to Upvote with the 👍 button for any post you find to be helpful.

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          • JKnottJ
            JKnott @Gooberpatrol66
            last edited by

            @Gooberpatrol66

            Correct. Since DHCPv6 isn't used, there are no leases.

            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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            • MikeV7896M
              MikeV7896
              last edited by MikeV7896

              The only way to get DHCPv6 hostnames with pfSense is with client self-registration using dynamic DNS. Unfortunately the ISC DHCPv6 server (used by FreeBSD, and thus pfSense) does not track hostnames for IPv6 leases, like it does for IPv4.

              I've never implemented such DDNS self-registration, so can't say for certain, but as long as your 10.0.0.1 device is running an authoritative DNS Server, like BIND, that sounds relatively correct what you've done. Of course, there's likely configuration needed on the DNS server side to accept the DDNS data from the clients.

              As far as SLAAC goes...

              SLAAC is completely stateless. It's fully on the client to determine the IPv6 address it will use, and to make sure it's not in use before using it. There is no definitive list of what addresses are being used. The closest list available is the Diagnostics > NDP Table list, which is a list of all IPv6 addresses found through network discovery. No hostnames are included on the list (though MAC addresses are included), and if you do use DHCPv6, those addresses will also appear on the list, since it's ALL IPv6 addresses discovered on the network(s).

              As far as a "consistent" address with SLAAC... if you don't want a SLAAC address to change, you need to disable privacy extensions on each client device. Windows, MacOS, and many Linux distros have privacy extensions enabled by default, so the host portion of the IPv6 address will change on a relatively regular interval (often at least once a day). It's possible to disable privacy extensions in all three of those operating systems, but not so much in Apple's iOS devices. I don't think Android allows disabling them either. With privacy extensions disabled, the address will usually be generated based on the MAC address of the interface. Do be aware that this can easily enable tracking across networks, since in theory your MAC address is unique to your device, so no one else will have it.

              The S in IOT stands for Security

              JKnottJ Bob.DigB 2 Replies Last reply Reply Quote 1
              • JKnottJ
                JKnott @MikeV7896
                last edited by

                @virgiliomi said in Understanding how to get hostnames in IPv6 leases:

                s far as a "consistent" address with SLAAC... if you don't want a SLAAC address to change, you need to disable privacy extensions on each client device.

                Regardless of whether privacy addresses are used, you will have one consistent address, either MAC or random number based. On my Linux system it's MAC based. On Windows 10, it was random number, which I changed to MAC. You only use the consistent address for DNS, as the privacy addresses only last for a week and you'll have up to 7 of them.

                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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                • G
                  Gooberpatrol66
                  last edited by

                  And if I have an ethernet bond and use SLAAC then the address of the bond will remain consistent?

                  JKnottJ 1 Reply Last reply Reply Quote 0
                  • JKnottJ
                    JKnott @Gooberpatrol66
                    last edited by

                    @Gooberpatrol66

                    What do you mean by "ethernet bond"? When you get an IPv6 address with SLAAC you will get at least a consistent address.

                    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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                    • G
                      Gooberpatrol66
                      last edited by Gooberpatrol66

                      LACP Link aggregation

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                      • Bob.DigB
                        Bob.Dig LAYER 8 @MikeV7896
                        last edited by Bob.Dig

                        @virgiliomi said in Understanding how to get hostnames in IPv6 leases:

                        Unfortunately the ISC DHCPv6 server (used by FreeBSD, and thus pfSense) does not track hostnames for IPv6 leases, like it does for IPv4.

                        At least Static DHCP > Register DHCP static mappings in the DNS Resolver in Unbound does work for the DHCPv6 Server & RA too, for Static Mappings and the Hostname defined there. But often it takes a little bit longer.

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