Re: [v6ops] WGLC: draft-ietf-v6ops-unique-ipv6-prefix-per-host-02 - multiple prefixes per device

[Mark Andrews <[e-mail]>]

In message <[e-mail]>, Gert Doering writes:
>
> Hi,
>
> On Fri, Mar 17, 2017 at 10:26:33AM +1100, Mark Andrews wrote:
> > >
> > > Yes, one always needs cautious allocation policies. But still... /64
> > > is not enough in the general case, with today's link-layer media
> > > and today's IPv6 stacks. (We can have the argument about tomorrow
> > > some other time. :-)
> >
> > And PD allows for a node to do multiple PD requests.  Each router
> > doesn't need a pool of prefixes to answer PD requests from.  It can
> > do a upstream request to full fill the downstream request on demand.
>
> Technically, it could.  Administratively, I'm going to believe that
> when I see it - like, in a big enterprise network, individual /64s
> being routed randomly across the place because a wifi hotspot needed
> another prefix to hand out.

Why not?  It's not like it actually is hard to do this.  What I am
seeing here is IPv4 think being applied to IPv6 features.  Handing
out prefixes is a completely different problem to handing out
individual addresses.  There is zero need to break down the prefix
pool into regions like you had to break down the IPv4 address space
into subnets.

> > A coffee shop is a site or part of a site.  That site should have
> > a /48 with 65536 /64 subnets to further allocate.  Hosts draw from
> > that pool.  Yes, that does mean that there are lots of intra site
> > routing entries for /64's rather than for shorter prefix lengths.
> > That however shouldn't matter because it is not a excessive number
> > for even the most inexpensive router to handle and they are summaried
> > as a /48 in the global routing table.  Even with a few of /48 pools
> > from different ISPs it still isn't excessive.
>
> A coffee shop has a /48 today (or a /56, given that the RIR policies
> where changed based on extrapolations that a /48 for each SoHo customer
> connection might not be sustainable).
>
> If we suggest that hosts should "get a /48", and there a a number of
> customers in that coffee shop, then a /48-per-site is not going to
> be enough.

A site may have a single host, but hosts, in general, aren't sites.
And who is suggesting that hosts get a /48 for this?  I'm not.

> But seriously: how many visitors of said coffee shop would need
> more than a /64?  Yes, I've heard about the laptop with the VMs running,
> in multiple hierarchical virtual networks, and such.  How many of those
> laptops exist?  100, 1000?  This is totally niche.

Today, not many.  Tomorrow who knows.  We do however have a
provisioning protocol that will work.

> Normal users want their browsing, e-mail and corporate VPN to work.
>
> Gert Doering
>         -- NetMaster
> --
> have you enabled IPv6 on something today...?
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