Re: v6 subnet size for DSL & leased line customers

From: Mark Smith (no email)
Date: Tue Jan 01 2008 - 08:29:50 EST

  • Next message: Jeroen Massar: "Re: IPv6 Addressing Plans"

    On Tue, 1 Jan 2008 12:57:17 +0100
    Iljitsch van Beijnum <> wrote:

    >
    > On 31 dec 2007, at 1:24, Mark Smith wrote:
    >
    > > Another idea would be to give each non-/48 customer the
    > > first /56 out of each /48.
    >
    > Right, so you combine the downsides of both approaches.
    >
    > It doesn't work when ARIN does it:
    >

    Well, ARIN aren't running the Internet route tables. If they were, I'd
    assume they'd force AS6453 to do the right thing and aggregate their
    address space.

    > * 24.122.32.0/20 4.68.1.166 0 0 3356 6453
    > 11290 i
    > * 24.122.48.0/20 4.68.1.166 0 0 3356 6453
    > 11290 i
    > * 24.122.64.0/20 4.68.1.166 0 0 3356 6453
    > 11290 i
    > * 24.122.80.0/20 4.68.1.166 0 0 3356 6453
    > 11290 i
    > * 24.122.96.0/20 4.68.1.166 0 0 3356 6453
    > 11290 i
    > * 24.122.112.0/20 4.68.1.166 0 0 3356 6453
    > 11290 i
    > * 24.122.128.0/20 4.68.1.166 0 0 3356 6453
    > 11290 i
    > * 24.122.144.0/20 4.68.1.166 0 0 3356 6453
    > 11290 i
    > * 24.122.160.0/20 4.68.1.166 0 0 3356 6453
    > 11290 i
    > * 24.122.176.0/20 4.68.1.166 0 0 3356 6453
    > 11290 i
    > * 24.122.192.0/19 4.68.1.166 0 0 3356 6453
    > 11290 i
    > * 24.122.224.0/20 4.68.1.166 0 0 3356 6453
    > 11290 i
    > * 24.122.240.0/20 4.68.1.166 0 0 3356 6453
    > 11290 i
    >
    > And it's unlikely to work here: for those standard size blocks, you
    > really don't want any per-user config: you want those to be assigned
    > automatically. But for the /48s you do need per-user config, if only
    > that this user gets a /48. So these two block sizes can't
    > realistically come from the same (sub-) range.

    Maybe I'm not understanding this correctly. Are you saying that
    customers who have a /56 would get dynamic ones i.e. a different one
    each time they reconnect? If they've got a routed downstream topology,
    with multiple routers and subnets (because of course, they've got 256
    of them), I don't think customers will be very happy about having to
    renumber top /56 bits if e.g. they have a DSL line sync drop out and
    get a different /56.

    Static assignments of /56 to customers make sense to me, and that's the
    assumption I've made when suggesting the addressing scheme I proposed.
    Once you go static with /56s, you may as well make it easy for both
    yourself and the customer to move to a /48 that encompasses the
    original /56 (or configure the whole /48 for them from the outset).

    Regards,
    Mark.

    -- 
            "Sheep are slow and tasty, and therefore must remain constantly
             alert."
                                       - Bruce Schneier, "Beyond Fear"
    

  • Next message: Jeroen Massar: "Re: IPv6 Addressing Plans"





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