[arin-discuss] Trying to Understand IPV6

[Robert E. Seastrom]

Tim Howe <tim.h at bendtel.com> writes:

> On Mon, 13 Sep 2010 19:32:33 +0100 <michael.dillon at bt.com> wrote:
>> Anyone in this position should simply assign a /48 to every customer site
>> no matter how big or small. A one bedroom apartment gets a /48. A manufacturing
>> plant with 5 buildings including a 4-story office block, gets a /48. 
>> No exceptions.
>
> 	This is slightly different than I have been led to think...  It
> seems wise, when you know the customer has no intention of having
> multiple networks, to provide a /64. 

Stop right there.  How do you *know* that they have no intention of
having multiple networks...  *ever*?  Sure you might have strong
suspicions if they are residential, but I already run guest and
resident subnets at home and if I had kids I'd be running two more,
and that's without even thinking about things that are uncommon or
because I'm a network guy - they are what you can reasonably expect
will start showing up in appliance home router/firewall/AP stuff that
supports IPv6.

Fast forward 8 years from now.  Do you want to be kicking yourself or
having your successor's successor cursing your name for trying to
conserve IPv6 space instead of conserving the brain cells of network
engineers?

Why do you care how many subnets your customer uses?  There is a
business cost to every bit of understanding the customer's use case.
Understanding how many subnets they need is only relevant in the
austerity environment of IPv4, not in the new world of IPv6.

> Not because you fear wasting
> address space.  Currently, most folks will have a single IP (half of the
> connecting range to their provider) and their LAN in RFC1918 space using
> that address for NAT.  The IPv6 equiv to that would be a /64 connecting
> range and another /64 range to use for their LAN.  This has been my plan
> as most of these customers don't know (and don't wish to know) how to
> subnet v4, so I am sure handing them a /48 and expecting them to use it
> correctly is out of the question and unnecessary.  This seems to be what
> HE is doing for tunnel accounts.

I think HE is absolutely doing the right thing here.  Everyone gets a
/48.  No exceptions.  Why?  It makes things easy for you, the network
vendor.

> 	Anyone wanting/needing multiple networks (or who even thinks they
> might, and knows what a /48 is) can and should have a /48, no problem.
>
> 	I am just a small provider with mostly small business accounts
> and colo, so maybe my situation isn't typical...
>
> /64 per network
> /48 per customer with more than one network (so they can have /64 per network)
>
> 	Is this flawed or no longer the prevailing way of thinking?

It certainly is setting your competitors up with a way to effectively
sell against you.  If staying small is in your business plan, have at
it.  :-)

-r