[ale] IPv6 Subnetting

David Tomaschik david at systemoverlord.com
Tue Feb 15 17:35:56 EST 2011


On Tue, Feb 15, 2011 at 3:04 PM, Michael H. Warfield <mhw at wittsend.com> wrote:
> On Tue, 2011-02-15 at 12:56 -0500, Michael B. Trausch wrote:
>> On Tue, 2011-02-15 at 12:14 -0500, Michael H. Warfield wrote:
>> > Don't go there if you can avoid it.  We want to avoid IPv4 mind think
>> > here.
>> >
>> > If you need more than one subnet, you're suppose to get a larger
>> > allocation and the ISP should make one available.
>> >
>> > Per the standards...
>> >
>> > If you need 1 subnet you get a /64.  If you need more than one subnet,
>> > you should get a /48 but some ISPs such as freenet6 may break that
>> > down further and hand you a /56 which is still 256 subnets.  Yes, most
>> > ISPs should be handing you a /64 as a default.  That is per the
>> > standard if that's all you need and that will be the case with most
>> > residential customers.  If you need more, they should allocate you
>> > more or they are in violation of the standards.
>
>> Oh, indeed.
>
>> That said, I can imagine that there will be lots of ISPs that won't even
>> know how to handle such a request.  Hell, there are now, for IPv4, and
>> we've been running that for decades.
>
> There's one major difference.
>
> With IPv6 they already have to allocate you a routable network, even if
> it only has 1 subnet.  That's a /64.  It's not like allocating a single
> address with IPv4 and then you have to change the paradigm to a
> "routable subnet" the moment you allocate a block of addresses.  We've
> already crossed that threashold and now we're just haggling over the
> block size.  One would hope that these guys wouldn't be so penny ante
> that they don't have some corporate customers who will require multiple
> subnets, so they should have some clue as to how to deal with that and
> allocate it as well.  Look at some of the other threads on this list
> where people have gotten business calls v4 with multiple addresses and
> dealt with routers they can't "open" because the ISP won't let them.
> Tell you what.  We're all now in the same class.  Maybe they'll call it
> business class if you have more than one subnet.  Wouldn't surprise me
> but the reality is, it's only the bits in the subnet.  You're not
> changing your allocation infrastructure from single address based to
> routed subnet based.  You're there either way.  That gives me some hope
> for optimism (note line in my signature).

Now the challenge will be finding an ISP that gives me what I need: a
/56 (or even a /60 or something crazy like that would be fine with
me), decent speed, no restrictions (e.g., a neutral net connection)
and no crappy hardware getting in my way (e.g., a modem should be just
that: a device to convert from one physical interface to another, aka
OSI Layer 1 & 2).  Oh, and affordable as a state employee.  Picky,
aren't I?


-- 
David Tomaschik, RHCE, LPIC-1
System Administrator/Open Source Advocate
OpenPGP: 0x5DEA789B
http://systemoverlord.com
david at systemoverlord.com



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