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

    How to distribute IPv6 adresses to OpenVPN clients with changing prefixes via SLAAC

    Scheduled Pinned Locked Moved OpenVPN
    6 Posts 2 Posters 518 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.
    • J
      Jung-Fernmelder
      last edited by

      Dear Netgate-forum,

      the ISP changes the IPv6 prefix (prefix length 56 bit) once per day and after every disconnect (configuration change, mains or line disconnection).
      How can I distribute the IPv6 prefix via SLACC to OpenVPN clients? I'd like to configure OpenVPN to distribute the IPv6 adresses via the normal router advertisements which are used also by the local connected clients.
      At the moment the OpenVPN clients don't get IPv6 adresses, they have IPv4 connectivity only.

      Best regards

      Jung-Fernmelder

      JKnottJ 1 Reply Last reply Reply Quote 0
      • JKnottJ
        JKnott @Jung-Fernmelder
        last edited by

        @Jung-Fernmelder

        As I mentioned in my other reply to you, use Unique Local Addresses.

        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...

        J 1 Reply Last reply Reply Quote 0
        • J
          Jung-Fernmelder @JKnott
          last edited by Jung-Fernmelder

          @JKnott Thank you so much. I've tried to implement your tutorial and added this virtual IP:
          Screenshot (547).png
          And these are my OpenVPN tunnel settings:
          Screenshot (548).png
          The OpenVPN clients get an IPv6 adresse from the expected subnet, in example [fc:12:3456:7890:1234::1000], but they don't have any IPv6 connectivity. What did I configure wrong and how to configure it properly?

          JKnottJ 1 Reply Last reply Reply Quote 0
          • JKnottJ
            JKnott @Jung-Fernmelder
            last edited by

            @Jung-Fernmelder

            I suspect you may need to have both local and global addresses on the tunnel. I don't see a definite way to do that, though it might be possible to add a second range. Since your global address changes, you'd have to add a network by name rather than address. Someone who knows more about OpenVPN may have to help. Since my prefix doesn't change I was able to use one of my /64s for the tunnel.

            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...

            J 1 Reply Last reply Reply Quote 0
            • J
              Jung-Fernmelder @JKnott
              last edited by

              @JKnott said in How to distribute IPv6 adresses to OpenVPN clients with changing prefixes via SLAAC:

              I suspect you may need to have both local and global addresses on the tunnel.

              @JKnott said in How to distribute IPv6 adresses to OpenVPN clients with changing prefixes via SLAAC:

              Since your global address changes, you'd have to add a network by name rather than address.

              Both makes sense.
              How to add the network by name?

              JKnottJ 1 Reply Last reply Reply Quote 0
              • JKnottJ
                JKnott @Jung-Fernmelder
                last edited by

                @Jung-Fernmelder said in How to distribute IPv6 adresses to OpenVPN clients with changing prefixes via SLAAC:

                How to add the network by name?

                As I said, this would have to go to someone who's more familiar with OpenVPN. However, the global address is only necessary if you are going through the VPN & pfSense to the Internet. If you're accessing only your local network ULA is fine.

                I wish ISPs wouldn't do things like this that break IPv6.

                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
                • First post
                  Last post
                Copyright 2025 Rubicon Communications LLC (Netgate). All rights reserved.