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    Multiple ipv6-nets on LAN with DHCPv6

    Scheduled Pinned Locked Moved IPv6
    dhcpv6multiple nets
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    • H
      Hikari
      last edited by

      This is very interesting.

      I use DHCPv6 on my OpenWRT router because it's the one responsible for attributing fixed suffixes to each device and also their domain names, both from their MAC.

      If I'm not wrong, under RA, each device defines its own suffix, and it's not fixed. Is pfSense able to set each device's domain name?

      How do you do for one device to connect to another on the LAN? By their domain names?

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

        @Hikari

        With RAs and SLAAC, a device will have 1 consistent address, often based on the MAC, and up to 7 privacy addresses, with a new one every day. I assign a host name to the consistent address, using host overrides in the DNS server. It works well.

        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 1
        • H
          Hikari
          last edited by

          tnx, could you point doc that teaches how to configure it?

          Are we able to set the suffix of this consistent address, so we can call devices by their IPv6 address?

          Does pfSense support attributing a host name over our LAN domain to each device based on its MAC, so we can call them by their name?

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

            @Hikari

            There's nothing to configure. It just works that way. Pfsense sends out the RA to provide the prefix and the device provides the lower 64 bits.

            Here are my addresses. I used my unique local addresses, instead of GUA, but the principle is the same. Take a look at the last line and see how it compares with the others. That line is the consistent one and is based on the MAC.

            inet6 fd48:1a37:2160:0:3c77:80bb:c0cf:522e/64 scope global temporary dynamic
            inet6 fd48:1a37:2160:0:5b:1416:435d:a8f5/64 scope global temporary deprecated dynamic
            inet6 fd48:1a37:2160:0:a4fe:df21:d0ee:c629/64 scope global temporary deprecated dynamic
            inet6 fd48:1a37:2160:0:2879:7de0:b225:47ad/64 scope global temporary deprecated dynamic
            inet6 fd48:1a37:2160:0:6c73:9d33:6451:150/64 scope global temporary deprecated dynamic
            inet6 fd48:1a37:2160:0:ecf2:1a5c:e064:3b/64 scope global temporary deprecated dynamic
            inet6 fd48:1a37:2160:0:494a:77f3:e5c0:2ca6/64 scope global temporary deprecated dynamic
            inet6 fd48:1a37:2160:0:76d4:35ff:fe5b:f5fa/64 scope global dynamic mngtmpaddr

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

              Wouldn't it be better to be able to use different prefixes with DHCPv6 on the same interface or is this against the DHCP specs?
              To have to use host-overrides in the dns-server looks messy to me. How consistent is an ipv6-address not given by DHCPv6 to a machine anyway?

              JKnottJ 1 Reply Last reply Reply Quote 0
              • JKnottJ
                JKnott @Bob.Dig
                last edited by

                @bob-dig

                I don't know about DHCPv6, but with SLAAC, you can have as many prefixes as you want. IPv6 was designed with that in mind.

                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...

                Bob.DigB 1 Reply Last reply Reply Quote 0
                • Bob.DigB
                  Bob.Dig LAYER 8 @JKnott
                  last edited by

                  @jknott Ok, but where to make the IP to Hostname or DNS Connection, which is important, right?

                  JKnottJ 1 Reply Last reply Reply Quote 0
                  • JKnottJ
                    JKnott @Bob.Dig
                    last edited by

                    @bob-dig

                    You pick whatever consistent address you wish and create a DNS entry for it. For most of my devices, I use the unique local address on the pfsense DNS server, but for some of them I also use the GUA address on an external DNS server.

                    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...

                    Bob.DigB 1 Reply Last reply Reply Quote 0
                    • Bob.DigB
                      Bob.Dig LAYER 8 @JKnott
                      last edited by

                      @jknott Are those addresses consistent or do you manually define them on those hosts?

                      JKnottJ 1 Reply Last reply Reply Quote 0
                      • JKnottJ
                        JKnott @Bob.Dig
                        last edited by

                        @bob-dig

                        All the addresses appear automagically. One of each type is consistent, based on the MAC address. The privacy addresses are based on random numbers. The only thing I configure is the DNS entries, which I point to the consistent addresses. I do not ever use a privacy address for DNS, as it would only last for a week. It is also possible to have consistent addresses based on a random number, for those who are worried about someone tracking their MAC 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...

                        1 Reply Last reply Reply Quote 1
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