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

    [SOLVED] How to IPv6 on multiple LANS? Track interface only supports one.

    Scheduled Pinned Locked Moved IPv6
    6 Posts 3 Posters 1.3k 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.
    • R
      router_wang
      last edited by

      What do you do when you have multiple LAN's (LAN/WIFI/KIDS/WIFI_GUEST) and "track interface" is used on LAN, but you want to use IPv6 on other networks?

      1 Reply Last reply Reply Quote 0
      • DerelictD
        Derelict LAYER 8 Netgate
        last edited by

        You need a larger prefix delegation from your ISP. The available networks for track interface will be automatically adjusted based on the size of delegation received.

        ![Screen Shot 2018-04-01 at 11.13.19 AM.png](/public/imported_attachments/1/Screen Shot 2018-04-01 at 11.13.19 AM.png)
        ![Screen Shot 2018-04-01 at 11.13.19 AM.png_thumb](/public/imported_attachments/1/Screen Shot 2018-04-01 at 11.13.19 AM.png_thumb)

        Chattanooga, Tennessee, USA
        A comprehensive network diagram is worth 10,000 words and 15 conference calls.
        DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
        Do Not Chat For Help! NO_WAN_EGRESS(TM)

        1 Reply Last reply Reply Quote 0
        • R
          router_wang
          last edited by

          @Derelict:

          You need a larger prefix delegation from your ISP.

          This seems REALLY ridiculous to me. I have a /64 Which is 18 quintillion addresses (18billion*billion), and somehow I need MORE addresses to use a couple more networks. Does this sound completely bat$#1^ crazy to anyone else?

          To clarify, I'm not saying you're crazy, just the notion of needing more IPv6 subnets to do this is crazy.

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

            @router_wang:

            What do you do when you have multiple LAN's (LAN/WIFI/KIDS/WIFI_GUEST) and "track interface" is used on LAN, but you want to use IPv6 on other networks?

            As mentioned by Derelict, you need a prefix that's larger than a single /64.  I have a /56, which provides 256 /64s.  Then when you create a LAN interface, you again track the WAN interface, but also select an IPv6 Prefix ID, to chose which of the /64s to use on that interface.

            This seems REALLY ridiculous to me. I have a /64 Which is 18 quintillion addresses (18billion*billion), and somehow I need MORE addresses to use a couple more networks. Does this sound completely bat$#1^ crazy to anyone else?

            The reason for this is the method used to automatically assign addresses.  With SLAAC, the MAC address is used to provide 64 bits of the device address.  It supports both 64 bit MACs and 48 bit, by inserting FFFE in the middle.  If you use some other means, such as DHCPv6 or manual configuration, you could get by with a smaller prefix, but it's not recommended.

            SLAAC
            https://en.wikipedia.org/wiki/IPv6#Stateless_address_autoconfiguration_.28SLAAC.29

            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
            • R
              router_wang
              last edited by

              Ah, it looks like I get a /60 so I got to go figure out prefix delegation and get it working.

              1 Reply Last reply Reply Quote 0
              • DerelictD
                Derelict LAYER 8 Netgate
                last edited by

                Do not think of an IPv6 prefix in terms of the number of addresses on a subnet. That is always /64.

                Think of it in terms of the number of /64 networks you have available to use on interfaces.

                /48 = 65536 /64s or 256 /56s for routing, delegation.
                /56 = 256 /64s
                /60 = 16 /64s

                You can call it ridiculous all you want. It is the way IPv6 is designed. Embrace it knowing you never ever ever have to worry about subnet size again.

                Chattanooga, Tennessee, USA
                A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                Do Not Chat For Help! NO_WAN_EGRESS(TM)

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