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    Ipv6 delegation/track interface explanation?

    Scheduled Pinned Locked Moved IPv6
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    • D
      dopey
      last edited by

      Can someone either provide me with an short primer on how ipv6 prefix delegation works, or provide me with a pointer to a good explanation of it?

      Also, what exactly does track interface do in the LAN ipv6 configuration?

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      • D
        dopey
        last edited by

        Perhaps i can explain what it is I'm running into as well to see if people have any ideas.

        i'm using comcast business class, and the comcast router (I have a /29 static ipv4 block) is configure to request a /56 from comcast.

        If I have pfsense request a /64, my WAN gets a /64:
        inet6 xxx prefixlen 64 autoconf

        And the LAN interface is tracking the WAn interface and it gets:
        inet6 xxx prefixlen 60
        a 60, so the local lan clients can't autoconfigure an IP address.

        If I set the prefix delegation size to /60, everything works, both WAN and LAN get a /64 and all is good.

        I really can't wrap my head around why this would be.

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        • H
          hda
          last edited by

          @dopey:

          …
          If I set the prefix delegation size to /60, everything works, both WAN and LAN get a /64 and all is good.

          I really can't wrap my head around why this would be.

          A prefix /60 gives you a collection of 2^4-1 subnets for your site. Each LAN, WAN node has its own unique subnet value, and such address has mask /64 …

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          • D
            dopey
            last edited by

            @hda:

            A prefix /60 gives you a collection of 2^4-1 subnets for your site. Each LAN, WAN node has its own unique subnet value, and such address has mask /64 …

            Thanks for confirming that.  That's what i had guessed was occurring. 
            But how would something like this work of the ISP does'nt provide you a /56.  For example, if their router only requested a /60, how would one allocate IPv6 addresses to WAN/LAN?

            Also, why is this occurring when I try to request a /64:
            And the LAN interface is tracking the WAn interface and it gets:
              inet6 xxx prefixlen 60

            Where is the LAN interface getting this /60?

            Thanks.

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